code: def upscale_height(images, scale):
      """Box upscaling along the H (axis=1) dimension.
  
      Args:
        images: A 4D `Tensor` in NHWC format.
        scale: A positive integer scale.
  
      Returns:
        A 4D `Tensor` of `images` up scaled by a factor `scale`.
  
      Raises:
        ValueError: If `scale` is not a positive integer.
      """
      scale = _get_validated_scale(scale)
      if scale == 1:
          return images
      images = tf.batch_to_space_nd(
          tf.tile(images, [scale, 1, 1, 1]),
          block_shape=[scale],
          crops=[[0, 0]],
      )
      return images
  
file_path: magenta/magenta/models/gansynth/lib/layers.py
imports: import numpy
  import tensorflow.compat.v1
label_desc: Use image node_id 6 for calling a global function with example usage: upscale_height(images, scale) and returns: images, images