<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def drain_transport(self):
		'''
		"Drain" the transport connection.

		This command simply returns all waiting messages sent from the remote chrome
		instance. This can be useful when waiting for a specific asynchronous message
		from chrome, but higher level calls are better suited for managing wait-for-message
		type needs.

		'''
		self.transport.check_process_ded()
		ret = self.transport.drain(tab_key=self.tab_id)
		self.transport.check_process_ded()
		return ret