code: def unregister(self, entry_point):
          
          if entry_point not in self.registered_extensions:
              raise ValueError('Extension not registered')
  
          ep = EntryPoint.parse(entry_point)
          self.registered_extensions.remove(entry_point)
          if self._extensions_by_name is not None:
              del self._extensions_by_name[ep.name]
          for i, ext in enumerate(self.extensions):
              if ext.name == ep.name:
                  del self.extensions[i]
                  break
docs: Unregister a provider
  
          :param str entry_point: provider to unregister (entry point syntax).