code: def from_directory(cls, directory):
          
          cert_path = os.path.join(directory, 'skein.crt')
          key_path = os.path.join(directory, 'skein.pem')
          for path, name in [(cert_path, 'cert'), (key_path, 'key')]:
              if not os.path.exists(path):
                  raise context.FileNotFoundError(
                      "Security %s file not found at %r" % (name, path)
                  )
          return Security(cert_file=cert_path, key_file=key_path)
docs: Create a security object from a directory.
  
          Relies on standard names for each file (``skein.crt`` and
          ``skein.pem``).