function testFrom_ThrowsAlreadyCalled() {
  var query = new lf.query.DeleteBuilder(hr.db.getGlobal());

  var buildQuery = function() {
    var e = db.getSchema().getEmployee();
    query.from(e).from(e);
  };

  // 515: from() has already been called.
  lf.testing.util.assertThrowsError(515, buildQuery);
}
Tests that Delete#from() fails if from() has already been called.