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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _find_project_config_file(user_config_file):
 """Find path to project-wide config file Search from current working directory, and traverse path up to directory with .versionner.rc file or root directory :param user_config_file: instance with user-wide config path :type: pathlib.Path :rtype: pathlib.Path """

    proj_cfg_dir = pathlib.Path('.').absolute()
    proj_cfg_file = None
    root = pathlib.Path('/')
    while proj_cfg_dir != root:
        proj_cfg_file = proj_cfg_dir / defaults.RC_FILENAME
        if proj_cfg_file.exists():
            break

        proj_cfg_file = None
        # pylint: disable=redefined-variable-type
        proj_cfg_dir = proj_cfg_dir.parent

    if proj_cfg_file and proj_cfg_file != user_config_file:
        return proj_cfg_file