def is_cell_empty ( self, row, col ):
        return (self.get_value( row, col ) is None)
Add single entry to SchemaEntries by invoking add_entry.
dataset/ETHPy150Open enthought/traitsui/traitsui/wx/table_model.py/TableModel.is_cell_empty--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/ext/ndb/prospective_search.py/_add_schema_entry