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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def combine_hashes(hashes):
 """A simple helper function to combine other hashes. Sorts the hashes before rolling them in."""

  hasher = sha1()
  for h in sorted(hashes):
    h = ensure_binary(h)
    hasher.update(h)
  return hasher.hexdigest() if PY3 else hasher.hexdigest().decode('utf-8')