function testExec_ThrowsMissingValues() {
  var query = new lf.query.InsertBuilder(hr.db.getGlobal());
  query.into(db.getSchema().getJob());
  // 518: Invalid usage of insert().
  return lf.testing.util.assertPromiseReject(518, query.exec());
}
Tests that Insert#exec() fails if values() has not been called first.
@return {!IThenable}