human
Complete this python program:
def find_dependent_tables(tables, graph=None):
assistant
#Here is the Python code you requested.

    """Recursively find all tables which depend on the given tables.
    The returned set does not include the original tables.
    """
    if (graph is None):
        graph = _pokedex_graph
    tables = list(tables)
    dependents = set()
    def add_dependents_of(table):
        for dependent_table in graph.get(table, []):
            if (dependent_table not in dependents):
                dependents.add(dependent_table)
                add_dependents_of(dependent_table)
    for table in tables:
        add_dependents_of(table)
    dependents -= set(tables)
    return dependents