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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 _check_load_paths(load_path):
    '''
    Checks the validity of the load_path, returns a sanitized version
    with invalid paths removed.
    '''
    if load_path is None or not isinstance(load_path, six.string_types):
        return None

    _paths = []

    for _path in load_path.split(':'):
        if os.path.isabs(_path) and os.path.isdir(_path):
            _paths.append(_path)
        else:
            log.info('Invalid augeas_cfg load_path entry: %s removed', _path)

    if not _paths:
        return None

    return ':'.join(_paths)