new_contents: import gc
  
  # functools.wraps breaks the pytest fixtures, so we have to use this
  # thid-party package
  import decorator
  import psutil
  
  
  def leakcheck(fn):
      # Compare the memory (after GC) before and after the test to determine
      # if we leaked memory
      def wrapper(fn, *args, **kwargs):
          gc.collect()
          mem_before = psutil.Process().memory_info()
          rv = fn(*args, **kwargs)
          gc.collect()
          mem_after = psutil.Process().memory_info()
          assert mem_before >= mem_after
          return rv
      return decorator.decorate(fn, wrapper)
  
subject: Add missing util module for tests