Cutting off the Internet: Testing Applications That Use Requests

requests is a very popular library for making HTTP requests in Python. Even though so many people use it, there's no thorough and exhaustive way to test applications that take advantage of it.

These slides are best read while listening to the presentation given at PyTennessee on 7 February 2015

Transcript

1. Testing applications that use requests
   Cutting off the Internet
   

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3. Object Placeholder
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4. 4
   • github3.py
   • twine
   • urllib3
   • sqlobject
   • betamax
   @sigmavirus24 (Ian the RFC Reader)
   www.rackspace.com
   • requests
   • Flake8
   • chardet
   • requests-toolbelt
   • uritemplate.py
   

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5. Object Placeholder
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6. Why listen to me?
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7. Why listen to me?
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8. First, some review
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9. What is a unit of code?
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10. What is a unit test?
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11. What are
    collaborators?
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12. Why are they
    important?
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13. class Foo(object):
    def fiz(self, *args):
    pass
    A Collaborators Example…
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14. class Bar(object):
    def __init__(self):
    self.foo = Foo()
    def baz(self, *args):
    a = self.foo.fiz()
    # do stuff with a
    A Collaborators Example…
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15. What are integration
    tests?
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16. Reminder:
    Tests should be fast
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17. Time for some code
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18. def get_resource(session,
    resource,
    params=None,
    headers=None):
    What We’re Testing
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19. url = url_from(resource)
    kw = {‘headers’: headers,
    ‘params’: params}
    resp = session.get(url, **kw)
    if resp.ok:
    return resp
    resp.raise_for_status()
    What We’re Testing
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20. Why should we test
    this?
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21. Why should we test
    this?
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22. Why should we test
    this?
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23. Approach the first
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24. • responses
    • httpretty
    • requests-mock
    Available Libraries
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25. • responses
    • httpretty
    • requests-mock
    Available Libraries
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26. import my_module
    import responses
    import requests
    Our First Test
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27. @responses.activate
    def test_get_resource():
    Our First Test
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28. responses.add(
    responses.GET,
    ‘https://api.github.com/users’,
    body=('[{"id": 1, "url": “https://'
    'api.github.com/user/foo”}]'),
    status=200,
    content_type=‘application/json')
    Our First Test
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29. session = requests.Session()
    resp = my_module.get_resource(
    session,
    ‘/users’)
    assert resp.json() is not None
    Our First Test
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30. $ py.test responses_ex.py
    responses_ex.py .
    Running Our First Test
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31. session = requests.Session()
    resp = my_module.get_resource(
    session, ‘/user’)
    assert resp.json() is not None
    Making Our Test Fail
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32. $ py.test responses_ex.py
    responses_ex.py F
    Making Our Test Fail
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33. $ py.test responses_ex.py
    responses_ex.py F
    ...
    ConnectionError: Connection
    refused: https://api.github.com/
    user
    Making Our Test Fail
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34. responses.calls
    responses.calls[0].request
    Inspecting the Requests Made
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35. Why is this good?
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36. Why is this
    insufficient?
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37. { "id": 3710711, "name": "github3.py", "full_name": "sigmavirus24/github3.py", "owner": { "login": "sigmavirus24", "id": 240830,
    "avatar_url": "https://avatars.githubusercontent.com/u/240830?v=3", "gravatar_id": "", "url": "https://api.github.com/users/sigmavirus24",
    "html_url": "https://github.com/sigmavirus24", "followers_url": "https://api.github.com/users/sigmavirus24/followers", "following_url":
    "https://api.github.com/users/sigmavirus24/following{/other_user}", "gists_url": "https://api.github.com/users/sigmavirus24/gists{/
    gist_id}", "starred_url": "https://api.github.com/users/sigmavirus24/starred{/owner}{/repo}", "subscriptions_url": "https://api.github.com/
    users/sigmavirus24/subscriptions", "organizations_url": "https://api.github.com/users/sigmavirus24/orgs", "repos_url": "https://
    api.github.com/users/sigmavirus24/repos", "events_url": "https://api.github.com/users/sigmavirus24/events{/privacy}",
    "received_events_url": "https://api.github.com/users/sigmavirus24/received_events", "type": "User", "site_admin": false }, "private":
    false, "html_url": "https://github.com/sigmavirus24/github3.py", "description": "Python library for interfacing with the GitHub APIv3",
    "fork": false, "url": "https://api.github.com/repos/sigmavirus24/github3.py", "forks_url": "https://api.github.com/repos/sigmavirus24/
    github3.py/forks", "keys_url": "https://api.github.com/repos/sigmavirus24/github3.py/keys{/key_id}", "collaborators_url": "https://
    api.github.com/repos/sigmavirus24/github3.py/collaborators{/collaborator}", "teams_url": "https://api.github.com/repos/sigmavirus24/
    github3.py/teams", "hooks_url": "https://api.github.com/repos/sigmavirus24/github3.py/hooks", "issue_events_url": "https://api.github.com/
    repos/sigmavirus24/github3.py/issues/events{/number}", "events_url": "https://api.github.com/repos/sigmavirus24/github3.py/events",
    "assignees_url": "https://api.github.com/repos/sigmavirus24/github3.py/assignees{/user}", "branches_url": "https://api.github.com/repos/
    sigmavirus24/github3.py/branches{/branch}", "tags_url": "https://api.github.com/repos/sigmavirus24/github3.py/tags", "blobs_url": "https://
    api.github.com/repos/sigmavirus24/github3.py/git/blobs{/sha}", "git_tags_url": "https://api.github.com/repos/sigmavirus24/github3.py/git/
    tags{/sha}", "git_refs_url": "https://api.github.com/repos/sigmavirus24/github3.py/git/refs{/sha}", "trees_url": "https://api.github.com/
    repos/sigmavirus24/github3.py/git/trees{/sha}", "statuses_url": "https://api.github.com/repos/sigmavirus24/github3.py/statuses/{sha}",
    "languages_url": "https://api.github.com/repos/sigmavirus24/github3.py/languages", "stargazers_url": "https://api.github.com/repos/
    sigmavirus24/github3.py/stargazers", "contributors_url": "https://api.github.com/repos/sigmavirus24/github3.py/contributors",
    "subscribers_url": "https://api.github.com/repos/sigmavirus24/github3.py/subscribers", "subscription_url": "https://api.github.com/repos/
    sigmavirus24/github3.py/subscription", "commits_url": "https://api.github.com/repos/sigmavirus24/github3.py/commits{/sha}",
    "git_commits_url": "https://api.github.com/repos/sigmavirus24/github3.py/git/commits{/sha}", "comments_url": "https://api.github.com/repos/
    sigmavirus24/github3.py/comments{/number}", "issue_comment_url": "https://api.github.com/repos/sigmavirus24/github3.py/issues/comments/
    {number}", "contents_url": "https://api.github.com/repos/sigmavirus24/github3.py/contents/{+path}", "compare_url": "https://api.github.com/
    repos/sigmavirus24/github3.py/compare/{base}...{head}", "merges_url": "https://api.github.com/repos/sigmavirus24/github3.py/merges",
    "archive_url": "https://api.github.com/repos/sigmavirus24/github3.py/{archive_format}{/ref}", "downloads_url": "https://api.github.com/
    repos/sigmavirus24/github3.py/downloads", "issues_url": "https://api.github.com/repos/sigmavirus24/github3.py/issues{/number}",
    "pulls_url": "https://api.github.com/repos/sigmavirus24/github3.py/pulls{/number}", "milestones_url": "https://api.github.com/repos/
    sigmavirus24/github3.py/milestones{/number}", "notifications_url": "https://api.github.com/repos/sigmavirus24/github3.py/notifications{?
    since,all,participating}", "labels_url": "https://api.github.com/repos/sigmavirus24/github3.py/labels{/name}", "releases_url": "https://
    api.github.com/repos/sigmavirus24/github3.py/releases{/id}", "created_at": "2012-03-13T19:58:53Z", "updated_at": "2015-01-15T08:07:34Z",
    "pushed_at": "2015-01-08T04:36:37Z", "git_url": "git://github.com/sigmavirus24/github3.py.git", "ssh_url": "git@github.com:sigmavirus24/
    github3.py.git", "clone_url": "https://github.com/sigmavirus24/github3.py.git", "svn_url": "https://github.com/sigmavirus24/github3.py",
    "homepage": "http://github3py.readthedocs.org/", "size": 8669, "stargazers_count": 268, "watchers_count": 268, "language": "Python",
    "has_issues": true, "has_downloads": true, "has_wiki": false, "has_pages": true, "forks_count": 91, "mirror_url": null,
    "open_issues_count": 22, "forks": 91, "open_issues": 22, "watchers": 268, "default_branch": "develop", "network_count": 91,
    "subscribers_count": 24 }
    Gigantic Resources
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38. { "id": 3710711, "name": "github3.py", "full_name": "sigmavirus24/github3.py", "owner": { "login": "sigmavirus24", "id": 240830,
    "avatar_url": "https://avatars.githubusercontent.com/u/240830?v=3", "gravatar_id": "", "url": "https://api.github.com/users/sigmavirus24",
    "html_url": "https://github.com/sigmavirus24", "followers_url": "https://api.github.com/users/sigmavirus24/followers", "following_url":
    "https://api.github.com/users/sigmavirus24/following{/other_user}", "gists_url": "https://api.github.com/users/sigmavirus24/gists{/
    gist_id}", "starred_url": "https://api.github.com/users/sigmavirus24/starred{/owner}{/repo}", "subscriptions_url": "https://api.github.com/
    users/sigmavirus24/subscriptions", "organizations_url": "https://api.github.com/users/sigmavirus24/orgs", "repos_url": "https://
    api.github.com/users/sigmavirus24/repos", "events_url": "https://api.github.com/users/sigmavirus24/events{/privacy}",
    "received_events_url": "https://api.github.com/users/sigmavirus24/received_events", "type": "User", "site_admin": false }, "private":
    false, "html_url": "https://github.com/sigmavirus24/github3.py", "description": "Python library for interfacing with the GitHub APIv3",
    "fork": false, "url": "https://api.github.com/repos/sigmavirus24/github3.py", "forks_url": "https://api.github.com/repos/sigmavirus24/
    github3.py/forks", "keys_url": "https://api.github.com/repos/sigmavirus24/github3.py/keys{/key_id}", "collaborators_url": "https://
    api.github.com/repos/sigmavirus24/github3.py/collaborators{/collaborator}", "teams_url": "https://api.github.com/repos/sigmavirus24/
    github3.py/teams", "hooks_url": "https://api.github.com/repos/sigmavirus24/github3.py/hooks", "issue_events_url": "https://api.github.com/
    repos/sigmavirus24/github3.py/issues/events{/number}", "events_url": "https://api.github.com/repos/sigmavirus24/github3.py/events",
    "assignees_url": "https://api.github.com/repos/sigmavirus24/github3.py/assignees{/user}", "branches_url": "https://api.github.com/repos/
    sigmavirus24/github3.py/branches{/branch}", "tags_url": "https://api.github.com/repos/sigmavirus24/github3.py/tags", "blobs_url": "https://
    api.github.com/repos/sigmavirus24/github3.py/git/blobs{/sha}", "git_tags_url": "https://api.github.com/repos/sigmavirus24/github3.py/git/
    tags{/sha}", "git_refs_url": "https://api.github.com/repos/sigmavirus24/github3.py/git/refs{/sha}", "trees_url": "https://api.github.com/
    repos/sigmavirus24/github3.py/git/trees{/sha}", "statuses_url": "https://api.github.com/repos/sigmavirus24/github3.py/statuses/{sha}",
    "languages_url": "https://api.github.com/repos/sigmavirus24/github3.py/languages", "stargazers_url": "https://api.github.com/repos/
    sigmavirus24/github3.py/stargazers", "contributors_url": "https://api.github.com/repos/sigmavirus24/github3.py/contributors",
    "subscribers_url": "https://api.github.com/repos/sigmavirus24/github3.py/subscribers", "subscription_url": "https://api.github.com/repos/
    sigmavirus24/github3.py/subscription", "commits_url": "https://api.github.com/repos/sigmavirus24/github3.py/commits{/sha}",
    "git_commits_url": "https://api.github.com/repos/sigmavirus24/github3.py/git/commits{/sha}", "comments_url": "https://api.github.com/repos/
    sigmavirus24/github3.py/comments{/number}", "issue_comment_url": "https://api.github.com/repos/sigmavirus24/github3.py/issues/comments/
    {number}", "contents_url": "https://api.github.com/repos/sigmavirus24/github3.py/contents/{+path}", "compare_url": "https://api.github.com/
    repos/sigmavirus24/github3.py/compare/{base}...{head}", "merges_url": "https://api.github.com/repos/sigmavirus24/github3.py/merges",
    "archive_url": "https://api.github.com/repos/sigmavirus24/github3.py/{archive_format}{/ref}", "downloads_url": "https://api.github.com/
    repos/sigmavirus24/github3.py/downloads", "issues_url": "https://api.github.com/repos/sigmavirus24/github3.py/issues{/number}",
    "pulls_url": "https://api.github.com/repos/sigmavirus24/github3.py/pulls{/number}", "milestones_url": "https://api.github.com/repos/
    sigmavirus24/github3.py/milestones{/number}", "notifications_url": "https://api.github.com/repos/sigmavirus24/github3.py/notifications{?
    since,all,participating}", "labels_url": "https://api.github.com/repos/sigmavirus24/github3.py/labels{/name}", "releases_url": "https://
    api.github.com/repos/sigmavirus24/github3.py/releases{/id}", "created_at": "2012-03-13T19:58:53Z", "updated_at": "2015-01-15T08:07:34Z",
    "pushed_at": "2015-01-08T04:36:37Z", "git_url": "git://github.com/sigmavirus24/github3.py.git", "ssh_url": "git@github.com:sigmavirus24/
    github3.py.git", "clone_url": "https://github.com/sigmavirus24/github3.py.git", "svn_url": "https://github.com/sigmavirus24/github3.py",
    "homepage": "http://github3py.readthedocs.org/", "size": 8669, "stargazers_count": 268, "watchers_count": 268, "language": "Python",
    "has_issues": true, "has_downloads": true, "has_wiki": false, "has_pages": true, "forks_count": 91, "mirror_url": null,
    "open_issues_count": 22, "forks": 91, "open_issues": 22, "watchers": 268, "default_branch": "develop", "network_count": 91,
    "subscribers_count": 24 }
    Gigantic Resources
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39. Using mock
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40. mocked_session = mock.MagicMock()
    my_module.get_resource(mocked_session,
    ‘/users’)
    mocked_session.get.assert_called_once_with(
    ‘https://api.github.com/users’,
    params=None, headers=None
    )
    Mocking Birds
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41. mocked_session = mock.MagicMock()
    my_module.get_resource(mocked_session,
    ‘/users’)
    mocked_session.get.assert_called_once_with(
    ‘https://api.github.com/users’,
    params=None, headers=None
    )
    Mocking Birds
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42. mocked_session = mock.MagicMock()
    my_module.get_resource(mocked_session,
    ‘/users’)
    mocked_session.get.assert_called_once_with(
    ‘https://api.github.com/users’,
    params=None, headers=None
    )
    Mocking Birds
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43. Approach the second
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44. session = requests.Session()
    response = get_resource(session,
    ‘/users’)
    assert response.ok
    Live Integration
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45. session = requests.Session()
    response = get_resource(session,
    ‘/users’)
    assert response.ok
    Live Integration
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    Now write and run 500 more of
    these
    

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46. session = requests.Session()
    response = get_resource(session,
    ‘/users’)
    assert response.ok
    Live Integration
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    Now write and run 500 more of
    these
    

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47. ......FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
    FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
    FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
    FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
    FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
    FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
    FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
    FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
    FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
    FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
    FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
    FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
    Giant Bucket of FFFFFFFFFFFFFFFFFFFFFFFFFFFail
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48. Approach the third
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49. • vcr.py
    • betamax
    Available Libraries
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50. • vcr.py
    • betamax
    Available Libraries
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51. session = requests.Session()
    with vcr.use_cassette(‘vcrexample.yml’):
    resp = my_module.get_resource(
    session, ‘/users’)
    assert response.ok
    users = resp.json()
    assert len(users) > 0
    Example with vcr.py
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52. session = requests.Session()
    with vcr.use_cassette(‘vcrexample.yml’):
    resp = my_module.get_resource(
    session, ‘/users’)
    assert response.ok
    users = resp.json()
    assert len(users) > 0
    Example with vcr.py
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53. session = requests.Session()
    with vcr.use_cassette(‘vcrexample.yml’):
    resp = my_module.get_resource(
    session, ‘/users’)
    assert response.ok
    users = resp.json()
    assert len(users) > 0
    Example with vcr.py
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54. session = requests.Session()
    recorder = betamax.Betamax(
    session, cassette_library_dir=‘.’)
    with recorder.use_cassette(‘betamaex’):
    resp = my_module.get_resource(
    session, ‘/users’)
    assert response.ok
    users = resp.json()
    assert len(users) > 0
    Example with betamax
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55. Example with betamax
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    session = requests.Session()
    recorder = betamax.Betamax(
    session, cassette_library_dir=‘.’)
    with recorder.use_cassette(‘betamaex’):
    resp = my_module.get_resource(
    session, ‘/users’)
    assert response.ok
    users = resp.json()
    assert len(users) > 0
    

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56. Example with betamax
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    session = requests.Session()
    recorder = betamax.Betamax(
    session, cassette_library_dir=‘.’)
    with recorder.use_cassette(‘betamaex’):
    resp = my_module.get_resource(
    session, ‘/users’)
    assert response.ok
    users = resp.json()
    assert len(users) > 0
    

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57. Example with betamax
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    session = requests.Session()
    recorder = betamax.Betamax(
    session, cassette_library_dir=‘.’)
    with recorder.use_cassette(‘betamaex’):
    resp = my_module.get_resource(
    session, ‘/users’)
    assert response.ok
    users = resp.json()
    assert len(users) > 0
    

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58. Reality
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59. Reality
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60. Reality
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61. THANK YOU
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    US SALES: 1-800-961-2888 | US SUPPORT: 1-800-961-4454 | WWW.RACKSPACE.COM
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