def test_two_children(
        self, childfree_tree_factory, mock_wrap_datatree_repr, mock_datatree_node_repr
    ):
        """
        Test with two level deep children.

        Uses a mock of _wrap_datatree_repr and datatree_node_repr to essentially mock
        the inline lambda function "lines_callback".
        """

        # Create mapping of children
        children = {"a": childfree_tree_factory(), "b": childfree_tree_factory()}

        # Expect first line to be produced from the first child, and
        # wrapped as _not_ the last child
        first_line = f"a {id(children['a'])} not end//"

        # Expect second line to be produced from the second child, and
        # wrapped as the last child
        second_line = f"b {id(children['b'])} end//"

        assert self.func(children) == (
            "<div style='display: inline-grid; grid-template-columns: 100%; grid-column: 1 / -1'>"
            f"{first_line}"
            f"{second_line}"
            "</div>"
        )

        Test with two level deep children.

        Uses a mock of _wrap_datatree_repr and datatree_node_repr to essentially mock
        the inline lambda function "lines_callback".
        
xarray/tests/test_formatting_html.py