code: def query(self, hostname, x509):
          
  
          key = self._x509_key(x509)
          try:
              pins = self._storage[hostname]
          except KeyError:
              return None
  
          if key in pins:
              return True
  
          return None
docs: Return true if the given :class:`OpenSSL.crypto.X509` object `x509` has
          previously been pinned for use with the given `hostname` and
          :data:`None` otherwise.
  
          Returning :data:`None` allows this method to be used with
          :class:`PinningPKIXCertificateVerifier`.