def data(value):
        """list or KeyedList of ``Data`` : Data definitions

        This defines the data being visualized. See the :class:`Data` class
        for details.
        """
        for i, entry in enumerate(value):
            _assert_is_type('data[{0}]'.format(i), entry,  Data)
list or KeyedList of ``Data`` : Data definitions

        This defines the data being visualized. See the :class:`Data` class
        for details.