如何将numpy数组的迭代器提供给tensorflow Estimator/Evaluable

import tensorflow as tf
import numpy as np

numpy_array = np.array([1, 2, 3, 4, 5])

numpy_iterator = iter(numpy_array)

def input_fn():
    dataset = tf.data.Dataset.from_generator(lambda: numpy_iterator, output_signature=tf.TensorSpec(shape=(), dtype=tf.int32))
    iterator = dataset.make_one_shot_iterator()
    features = iterator.get_next()
    return {'x': features}, None

estimator = tf.estimator.Estimator(model_fn=model_fn)

estimator.train(input_fn=input_fn)
estimator.evaluate(input_fn=input_fn)