Get(EchoRequest) returns (EchoResponse) {} rpc Expand(EchoRequest) returns (stream EchoResponse) {} ← serverStreaming rpc Collect(stream EchoRequest) returns (EchoResponse) {} ← clientStreaming rpc Update(stream EchoRequest) returns (stream EchoResponse) {} ← bidirectionalStreaming } message EchoRequest { // The text of a message to be echoed. string text = 1; } message EchoResponse { // The text of an echo response. string text = 1; } ← unaryStreaming