@staticmethod
def string_join(loader, node):
    """
        Yaml join list of string by given string as first param.
        usage: !string_join [param, ...]

        :param obj loader: PyYaml Loader.
        :param obj node: Pyyaml node.
        :return: joined string.
        """
    seq = loader.construct_sequence(node)
    return seq[0].join(seq[1:])
