def open(cls, typename):
		"""Create an OMAPI open message with given typename.
		@type typename: bytes
		@rtype: OmapiMessage
		"""
		return cls(opcode=OMAPI_OP_OPEN, message=[(b"type", typename)], tid=-1)
Create an OMAPI open message with given typename.
		@type typename: bytes
		@rtype: OmapiMessage