def METHOD_NAME(schema):
    """Generate contents of DDL file as a string."""
    gen = SQLTableGenerator(schema)
    ddl = gen.generate_ddl()
    tables = []
    for item in ddl.splitlines():
        res = re.search(r"\"(.*?)\"", item)
        if res:
            tables.append(res.group(1))
    expected_tables = [
        "NamedThing",
        "Place",
        "Address",
        "Event",
        "Concept",
        "DiagnosisConcept",
        "ProcedureConcept",
        "Relationship",
        "Container",
        "Person",
        "Address",
        "Organization",
    ]
    for expected in expected_tables:
        assert expected in tables