code: def add_capability_list(self, capability_list=None):
          
          if (hasattr(capability_list, 'uri')):
              r = Resource(uri=capability_list.uri,
                           capability=capability_list.capability_name)
              if (capability_list.describedby is not None):
                  r.link_set(rel='describedby', href=capability_list.describedby)
          else:
              r = Resource(uri=capability_list,
                           capability='capabilitylist')
          self.add(r)
docs: Add a capability list.
  
          Adds either a CapabiltyList object specified in capability_list
          or else creates a Resource with the URI given in capability_list
          and adds that to the Source Description