在 Keras-Tuner 中使用“RandomSearch Tuner”时无法从“search_space_summary()”中看到所有“Dense”层信息？

我正在尝试使用keras-tuner来调整超参数，例如

!pip install keras-tuner --upgrade
import keras_tuner as kt
from tensorflow.keras.models import Sequential
from tensorflow.keras.layers import Dense, Flatten
from tensorflow.keras.optimizers import Adam

def build_model(hp):
    model = Sequential([
        Flatten(input_shape=(28, 28)),
        Dense(units= hp.Int('units', min_value = 16, max_value = 64, step = 16), activation='relu'),
        Dense(units = hp.Int('units', min_value = 8, max_value = 20, step = 2), activation='softmax')
    ])

    model.compile(
        optimizer=Adam(learning_rate=hp.Float('learning_rate', min_value=1e-4, max_value=1e-2, sampling='LOG')),
        loss='sparse_categorical_crossentropy',
        metrics=['accuracy']
    )
    return model

# Create a RandomSearch Tuner
tuner = kt.RandomSearch(
    build_model, 
    objective='val_accuracy',
    max_trials=10,
    executions_per_trial=2
)

# Display a summary of the search space
tuner.search_space_summary()

节目

Search space summary
Default search space size: 2
units (Int)
{'default': None, 'conditions': [], 'min_value': 16, 'max_value': 64, 'step': 16, 'sampling': 'linear'}
learning_rate (Float)
{'default': 0.0001, 'conditions': [], 'min_value': 0.0001, 'max_value': 0.01, 'step': None, 'sampling': 'log'}

然而，检查search_space_summary()输出时，摘要中仅显示第一层，而看不到有关第二层（即）Dense的信息。DenseDense(units = hp.Int('units', min_value = 8, max_value = 20, step = 2), activation='softmax')

我是不是配置错误了，还是它应该输出这样的结果？有人能帮我理解为什么它会输出这样的摘要吗？