code: def forget(empowered, powerupClass, interface):
      
      className = fullyQualifiedName(powerupClass)
      withThisName = _StoredByName.className == className
      items = empowered.store.query(_StoredByName, withThisName)
  
      if items.count() == 0:
          template = "No named powerups for {} (interface: {})".format
          raise ValueError(template(powerupClass, interface))
  
      for stored in items:
          empowered.powerDown(stored, interface)
          stored.deleteFromStore()
docs: Forgets powerups previously stored with ``remember``.
  
      :param empowered: The Empowered (Store or Item) to be powered down.
      :type empowered: ``axiom.item.Empowered``
      :param powerupClass: The class for which powerups will be forgotten.
      :type powerupClass: class
      :param interface: The interface the powerups were installed for.
      :type interface: ``zope.interface.Interface``
      :returns: ``None``
      :raises ValueError: Class wasn't previously remembered.