'Check if the given path is a git submodule.
See the docstrings for ``_check_submodule_using_git`` and
``_check_submodule_no_git`` for further details.'

def _check_submodule(self):

    if ((self.path is None) or (os.path.exists(self.path) and (not os.path.isdir(self.path)))):
        return False
    if self.use_git:
        return self._check_submodule_using_git()
    else:
        return self._check_submodule_no_git()
