def abort(self, frame):
if not frame.transaction:<EOL><INDENT>raise ProtocolError("<STR_LIT>")<EOL><DEDENT>if not frame.transaction in self.engine.transactions:<EOL><INDENT>raise ProtocolError("<STR_LIT>" % frame.transaction)<EOL><DEDENT>self.engine.queue_manager.resend_transaction_frames(<EOL>self.engine.connection, frame.transaction)<EOL>del self.engine.transactions[frame.transaction]<EOL>
Handles ABORT command: Rolls back specified transaction.