@staticmethod
def simple_join(loader, node):
    """
        Yaml join list of string on empty string.
        usage: !join [param, ...]

        :param obj loader: PyYaml Loader.
        :param obj node: Pyyaml node.
        :return: joined string.
        """
    seq = loader.construct_sequence(node)
    return ''.join(seq)
