@staticmethod
def removable_cells(obj):
    """
        List object removable cells

        TESTS ::

            sage: from sage.combinat.tableau import Tableau
            sage: from sage_widget_adapters.combinat.tableau_grid_view_adapter import TableauGridViewAdapter
            sage: t = Tableau([[1, 2, 5, 6], [3, 7], [4]])
            sage: TableauGridViewAdapter.removable_cells(t)
            [(0, 3), (1, 1), (2, 0)]
        """
    return obj.corners()
