'Validate argument checking'

def test_command_args(self):

    self.assertCommandFailureRegexp('Error:    too    few    arguments')
    self.assertCommandFailureRegexp('Error:    unrecognized    arguments:    blah    blah    blah', 'blah', 'blah', 'blah', 'blah')
    self.assertCommandFailureRegexp("Path    {0}    doesn't    exist,    please    create    it,".format(self.git_repo_dir), 'blah')
    if (not os.path.isdir(self.git_repo_dir)):
        os.mkdir(self.git_repo_dir)
    self.addCleanup(shutil.rmtree, self.git_repo_dir)
    if (not os.path.isdir((self.git_repo_dir / 'edx4edx'))):
        os.mkdir((self.git_repo_dir / 'edx4edx'))
    call_command('git_add_course', self.TEST_REPO, directory_path=(self.git_repo_dir / 'edx4edx_lite'))
    call_command('git_add_course', self.TEST_REPO, directory_path=(self.git_repo_dir / 'edx4edx_lite'), repository_branch=self.TEST_BRANCH)
