Keras tuner stop search from callback

Question

I am using keras tuner to serach for hyperparameters. If there are no improvement after certain number of trials then I would like to stop searching. Is it possible to do via callback fucntion?

class EarlySearchStop(Callback):
    def __init__(self, patience=5):
      super(EarlySearchStop, self).__init__()
      self.patience = patience
      self.best_metric = float('inf')
      self.wait = 0     

    def on_train_end(self, logs=None):
      if some_global_minimum < self.best_metric: 
          stop_searching_toomuch()

So far, I can stop "a trial" on epoch end. However, I am looking to stop the whole search space.