docs: def find(self, oid):
          """
          Return list of extensions with given Oid
          """
          if not isinstance(oid, Oid):
              raise TypeError("Need crytypescrypto.oid.Oid as argument")
          found = []
          index = -1
          end = len(self)
          while True:
              index = libcrypto.X509_get_ext_by_NID(self.cert.cert, oid.nid,
                                                    index)
              if index >= end or index < 0:
                  break
              found.append(self[index])
          return found