code: def test_get_output_shape_for_outdim3(self, layer_outdim3):
      input_shape = (2, 3, 4, 5)
      assert layer_outdim3.get_output_shape_for(input_shape) == (
          2,
          3,
          4 * 5,
      )
  
imports: import numpy
  import pytest
  import theano
  from mock import Mock
label_desc: Use image node_id 7 for calling the TestFlattenLayer obj's underlying member method code with example usage: obj.test_get_output_shape_for_outdim3(layer_outdim3) without return types