docs: def decrypt_file(self, encrypted_file, passphrase, signer_key=None,
                       always_trust=False, output_filename=None):
          '''
          Decrypt/verify file
  
          :param encrypted_file: File-like object containing encrypted data
          :param passphrase: Passphrase
          :param signer_key: Signer key ID. Sign will not be verifyed when None
          :param always_trust: Skip key validation and assume that used keys are always fully trusted
          :param output_filename: Decrypted data will be written to this file when not None
          :rtype: EncryptResult
          '''
          args = ['--decrypt']
          if signer_key:
              args += ('-u', signer_key)
          if output_filename:
              if os.path.exists(output_filename):
                  # to avoid overwrite confirmation message
                  os.remove(output_filename)
              args += ('--output', output_filename)
          if always_trust:
              #args.append ('--always-trust')
              args += ('--trust-model', 'always')
          return self.execute(DecryptResult(), args, passphrase, encrypted_file, True)