code: def get_namespace_hash(self, hash_fn=hashlib.md5) -> str:
          
          m = hash_fn()
  
          if self.has_names:
              items = self._get_namespace_name_to_encoding(desc='getting hash').items()
          else:
              items = self._get_namespace_identifier_to_encoding(desc='getting hash').items()
  
          for name, encoding in items:
              m.update(f'{name}:{encoding}'.encode('utf8'))
          return m.hexdigest()
docs: Get the namespace hash.
  
          Defaults to MD5.