def test_install_pypi_onlybinary(self):
        """test 'pip install --only-binary :all: <pypi_package>'."""
        output = self.run_command("pip --verbose install --only-binary :all: rsa==4.5", exitcode=0)
        self.assertIn("Downloading package", output)
        self.assert_did_run_setup(output, allow_source=False)
        self.assertIn("Package installed: rsa", output)
        try:
            import benterfaces
        except ImportError as e:
            self.logger.info("sys.path = " + str(sys.path))
            raise AssertionError("Could not import installed module: " + repr(e))
test 'pip install --only-binary :all: <pypi_package>'.
tests/pip/test_pip.py