function testFrom_ThrowsAlreadyCalled() {
  var query = new lf.query.SelectBuilder(hr.db.getGlobal(), []);

  var buildQuery = function() {
    var jobTable = db.getSchema().getJob();
    var employeeTable = db.getSchema().getEmployee();
    query.from(jobTable).from(employeeTable);
  };

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