def format(keys, value, _type, prefix=""):
        """
        General format function.

        >>> StatsdClient.format("example.format", 2, "T")
        {'example.format': '2|T'}
        >>> StatsdClient.format(("example.format31", "example.format37"), "2",
        ... "T")
        {'example.format31': '2|T', 'example.format37': '2|T'}
        >>> StatsdClient.format("example.format", 2, "T", "prefix.")
        {'prefix.example.format': '2|T'}
        """
        data = {}
        value = "{0}|{1}".format(value, _type)
        # TODO: Allow any iterable except strings
        if not isinstance(keys, (list, tuple)):
            keys = [keys]
        for key in keys:
            data[prefix + key] = value
        return data
General format function.

        >>> StatsdClient.format("example.format", 2, "T")
        {'example.format': '2|T'}
        >>> StatsdClient.format(("example.format31", "example.format37"), "2",
        ... "T")
        {'example.format31': '2|T', 'example.format37': '2|T'}
        >>> StatsdClient.format("example.format", 2, "T", "prefix.")
        {'prefix.example.format': '2|T'}