text: # Copyright (c) 2016, 2018 Claudiu Popa <pcmanticore@gmail.com>
  # Copyright (c) 2018 David Poirier <david-poirier-csn@users.noreply.github.com>
  # Copyright (c) 2018 wgehalo <wgehalo@gmail.com>
  # Copyright (c) 2018 Ioana Tagirta <ioana.tagirta@gmail.com>
  
  # Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
  # For details: https://github.com/PyCQA/astroid/blob/master/COPYING.LESSER
  import sys
  
  import six
  
  import astroid
  
  PY36 = sys.version_info >= (3, 6)
  
  
  def _hashlib_transform():
      signature = "value=''"
      template = """
      class %(name)s(object):
        def __init__(self, %(signature)s): pass
        def digest(self):
          return %(digest)s
        def copy(self):
          return self
        def update(self, value): pass
        def hexdigest(self):
          return ''
        @property
        def name(self):
          return %(name)r
        @property
        def block_size(self):
          return 1
        @property
        def digest_size(self):
          return 1
      """
      algorithms_with_signature = dict.fromkeys(
          ["md5", "sha1", "sha224", "sha256", "sha384", "sha512"], signature
      )
      if PY36:
          blake2b_signature = "data=b'', *, digest_size=64, key=b'', salt=b'', \
                  person=b'', fanout=1, depth=1, leaf_size=0, node_offset=0, \
                  node_depth=0, inner_size=0, last_node=False"
          blake2s_signature = "data=b'', *, digest_size=32, key=b'', salt=b'', \
                  person=b'', fanout=1, depth=1, leaf_size=0, node_offset=0, \
                  node_depth=0, inner_size=0, last_node=False"
          new_algorithms = dict.fromkeys(
              ["sha3_224", "sha3_256", "sha3_384", "sha3_512", "shake_128", "shake_256"],
              signature,
          )
          algorithms_with_signature.update(new_algorithms)
          algorithms_with_signature.update(
              {"blake2b": blake2b_signature, "blake2s": blake2s_signature}
          )
      classes = "".join(
          template
          % {
              "name": hashfunc,
              "digest": 'b""' if six.PY3 else '""',
              "signature": signature,
          }
          for hashfunc, signature in algorithms_with_signature.items()
      )
      return astroid.parse(classes)
  
  
  astroid.register_module_extender(astroid.MANAGER, "hashlib", _hashlib_transform)
  