Ensure stream is not null when the transport is getting it from the StreamManager
Ensure stream is not null when the transport is getting it from the StreamManager

Summary: Ensure stream is not null when the transport is getting it from the StreamManager

Reviewed By: mjoras

Differential Revision: D39753796

fbshipit-source-id: bc2a870a26510267d972bb59758792696c99501d

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