code: def add_capability(self, capability=None, uri=None, name=None):
          
          if (capability is not None):
              name = capability.capability_name
              if (capability.uri is not None):
                  uri = capability.uri
          self.add(Resource(uri=uri, capability=name))
docs: Specific add function for capabilities.
  
          Takes either:
          - a capability object (derived from ListBase) as the first argument
            from which the capability name is extracted, and the URI if given
          - or a plain name string
          and
          - the URI of the capability