message: Add an explicit fake output stream adapter to encrypting_stream_test.
diff: @@ -30,9 +30,21 @@ B_AAD_ = b'aa' + B_X80
  B_ASSOC_ = b'asso' + B_X80
  +class FakeOutputStreamAdapter(object):
  +
  + def __init__(self, destination):
  + self._destination = destination
  +
  + def write(self, data):
  + return self._destination.write(data)
  +
  + def close(self):
  + self._destination.close()
  +
  +
  def fake_get_output_stream_adapter(self, cc_primitive, aad, destination):
  del cc_primitive, aad, self # unused
  - return destination
  + return FakeOutputStreamAdapter(destination)
  class TestBytesObject(io.BytesIO):
  