code: def testBuildDimError(self):
      mod = reshape.Flatten(preserve_dims=2)
      input_tensor = tf.ones([50])
      with self.assertRaisesRegex(
          ValueError, "should have at least as many as"
      ):
          mod(input_tensor)
  
imports: from absl.testing import parameterized
  import numpy
  from sonnet.src import reshape
  from sonnet.src import test_utils
  import tensorflow
label_desc: Use image node_id 8 for calling the FlattenTest obj's underlying member method code with example usage: obj.testBuildDimError() without return types