Main program for the child process run by twisted.test.test_stdio.StandardInputOutputTests.test_readConnectionLost
to test that IHalfCloseableProtocol.readConnectionLost works for process 
transports.
| Class | HalfCloseProtocol | A protocol to hook up to stdio and observe its transport being 
half-closed.  If all goes as expected, exitCodewill be set to0; otherwise it will be set to1to indicate 
failure. |