def _main(config, session):
config.hook.pytest_collection(session=session)<EOL>config.hook.pytest_runtestloop(session=session)<EOL>if session.testsfailed:<EOL><INDENT>return EXIT_TESTSFAILED<EOL><DEDENT>elif session.testscollected == <NUM_LIT:0>:<EOL><INDENT>return EXIT_NOTESTSCOLLECTED<EOL><DEDENT>
default command line protocol for initialization, session,
    running tests and reporting.