text: # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #    http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
  # implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  from cryptography.hazmat.backends import openssl
  from cryptography.hazmat.backends.multibackend import MultiBackend
  from cryptography.hazmat.bindings.commoncrypto.binding import (
      Binding as CommonCryptoBinding
  )
  
  _ALL_BACKENDS = []
  
  if CommonCryptoBinding.is_available():
      from cryptography.hazmat.backends import commoncrypto
      _ALL_BACKENDS.append(commoncrypto.backend)
  
  _ALL_BACKENDS.append(openssl.backend)
  
  
  _default_backend = MultiBackend(_ALL_BACKENDS)
  
  
  def default_backend():
      return _default_backend
  