code: def _compute_shape(self, input_shape):
      assert len(input_shape) == 3
      shape_to_return = [None, input_shape[-1]]
      return shape_to_return
  
imports: from __future__ import division
  from __future__ import print_function
  from __future__ import absolute_import
  from .core import *
  from .helper_functions import conv1d_transpose_via_conv2d
  from .convolutional import PaddingMode, DataFormat
  from .None import helper_functions
  import tensorflow
  from tensorflow.python.ops import nn_grad
label_desc: Use image node_id 2 for calling the GlobalMaxPool1D obj's underlying member method code with example usage: obj._compute_shape(input_shape) and returns: shape_to_return