old_contents: # coding: utf8
  from __future__ import unicode_literals
  
  import gc
  
  from ...lang.en import English
  
  
  def test_issue1506():
      nlp = English()
  
      def string_generator():
          for _ in range(10001):
              yield "It's sentence produced by that bug."
  
          yield "Oh snap."
  
          for _ in range(10001):
              yield "I erase lemmas."
  
          for _ in range(10001):
              yield "It's sentence produced by that bug."
  
          for _ in range(10001):
              yield "It's sentence produced by that bug."
  
      anchor = None
      remember = None
      for i, d in enumerate(nlp.pipe(string_generator())):
          if i == 9999:
              anchor = d
          elif 10001 == i:
              remember = d
          elif i == 10002:
              del anchor
              gc.collect()
  
          for t in d:
              str(t.lemma_)
  
      assert remember.text == 'Oh snap.'
  
new_contents: # coding: utf8
  from __future__ import unicode_literals
  
  import gc
  
  from ...lang.en import English
  
  
  def test_issue1506():
      nlp = English()
  
      def string_generator():
          for _ in range(10001):
              yield "It's sentence produced by that bug."
  
          yield "Oh snap."
  
          for _ in range(10001):
              yield "I erase lemmas."
  
          for _ in range(10001):
              yield "It's sentence produced by that bug."
  
          for _ in range(10001):
              yield "It's sentence produced by that bug."
  
      anchor = None
      remember = None
      for i, d in enumerate(nlp.pipe(string_generator())):
          if i == 9999:
              anchor = d
          elif 10001 == i:
              remember = d
          elif i == 10002:
              del anchor
              gc.collect()
  
          # We should run cleanup more than one time to actually cleanup data.
          # In first run — clean up only mark strings as «not hitted».
          if i == 20000 or i == 30000:
              gc.collect()
  
          for t in d:
              str(t.lemma_)
  
      assert remember.text == 'Oh snap.'
  
subject: Create test that fails when actual cleanup caused