Keras的输入如何区分不同特征

def build_model(batch_size, nb_sessions, session_size, dimension, nb_units):

    # inputs

    x= Input(batch_shape=(batch_size, nb_sessions, session_size, dimension))

x_hat= Input(batch_shape=(batch_size, 1, dimension))

s_hat= Input(batch_shape=(batch_size, 1, nb_units))

hist= model.fit([X, x0, s0], Y,

                batch_size=BATCH_SIZE,

                epochs=EPOCHS)