code: def test_concatenated_sequence():
      l1 = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
      l2 = ConcatenatedSequence(
          [0, 1], [], [2, 3, 4], [5, 6, 7, 8, 9], []
      )
  
      # __len__()
      assert len(l1) == len(l2)
  
      # index()
      for item in l1 + [999]:
          # no indices
          assert_equal_including_exceptions(
              lambda: l1.index(item), lambda: l2.index(item)
          )
  
          # only start index
          for index in range(-15, 15):
              assert_equal_including_exceptions(
                  lambda: l1.index(item, index),
                  lambda: l2.index(item, index),
              )
  
          # start and stop index
          for start_index in range(-15, 15):
              for end_index in range(-15, 15):
                  assert_equal_including_exceptions(
                      lambda: l1.index(item, start_index, end_index),
                      lambda: l2.index(item, start_index, end_index),
                  )
  
      # __getitem__()
      for index in range(-15, 15):
          assert_equal_including_exceptions(
              lambda: l1[index], lambda: l2[index]
          )
  
      for start_index in range(-15, 15):
          for end_index in range(-15, 15):
              assert_equal_including_exceptions(
                  lambda: l1[start_index:end_index],
                  lambda: list(l2[start_index:end_index]),
              )
  
      # count()
      for item in l1 + [999]:
          assert_equal_including_exceptions(
              lambda: l1.count(item), lambda: l2.count(item)
          )
  
      # __contains__()
      for item in l1 + [999]:
          assert_equal_including_exceptions(
              lambda: item in l1, lambda: item in l2
          )
  
imports: import pytest
  from allennlp.common.sequences import ConcatenatedSequence
label_desc: Use image node_id 2 for calling a global function with example usage: test_concatenated_sequence() without return types