'This is invoked by the connection when frames that are not registered
with the CallbackManager have been found. This should only be the case
when the frames are related to content delivery.
The _content_assembler will be invoked which will return the fully
formed message in three parts when all of the body frames have been
received.
:param pika.amqp_object.Frame frame_value: The frame to deliver'

def _handle_content_frame(self, frame_value):

    try:
        response = self._content_assembler.process(frame_value)
    except exceptions.UnexpectedFrameError:
        self._on_unexpected_frame(frame_value)
        return
    if response:
        if isinstance(response[0].method, spec.Basic.Deliver):
            self._on_deliver(*response)
        elif isinstance(response[0].method, spec.Basic.GetOk):
            self._on_getok(*response)
        elif isinstance(response[0].method, spec.Basic.Return):
            self._on_return(*response)
