human
Complete this python program:
def is_table(doctype):
assistant
#Here is the Python code you requested.

    """Returns True if `istable` property (indicating child Table) is set for given DocType.
    """
    def get_tables():
        return db.sql_list(u'select    name    from    tabDocType    where    istable=1')
    tables = cache().get_value(u'is_table', get_tables)
    return (doctype in tables)