code: def test_prefix_lm_last_output_batch_is_short(self):
      prefix_lm_fn = data.PrefixLM(input_length=2, output_length=3)
      examples = list(prefix_lm_fn([[1, 2, 3, 4, 5, 6, 7, 8]]))
      self.assertSequenceEqual(([1, 2], [3, 4, 5]), examples[0])
      self.assertSequenceEqual(([6, 7], [8]), examples[1])
      self.assertLen(examples, 2)
  
imports: import itertools
  import os
  from absl.testing import absltest
  from absl.testing import parameterized
  import numpy
  from trax import data
label_desc: Use image node_id 37 for calling the InputsTest obj's underlying member method code with example usage: obj.test_prefix_lm_last_output_batch_is_short() without return types