'Add mapping for form.
Args:
cells (dict): A dictionary of {identifier:celltext}
tables (dict): A dictionary of {identifier:table}
Notes:
kwargs will be forwarded to tables/cells. See
`evtable.EvCell` and `evtable.EvTable` for info.'

def map(self, cells=None, tables=None, **kwargs):

    kwargs.pop('enforce_size', None)
    kwargs.pop('width', None)
    kwargs.pop('height', None)
    new_cells = (dict(((to_str(key, force_string=True), value) for (key, value) in cells.items())) if cells else {})
    new_tables = (dict(((to_str(key, force_string=True), value) for (key, value) in tables.items())) if tables else {})
    self.cells_mapping.update(new_cells)
    self.tables_mapping.update(new_tables)
    self.reload()
