docs: public static List<TriggerDescriptor> for_(Item i) {
          List<TriggerDescriptor> r = new ArrayList<>();
          for (TriggerDescriptor t : all()) {
              if(!t.isApplicable(i))  continue;
  
              if (i instanceof TopLevelItem) {// ugly
                  TopLevelItemDescriptor tld = ((TopLevelItem) i).getDescriptor();
                  // tld shouldn't be really null in contract, but we often write test Describables that
                  // doesn't have a Descriptor.
                  if(tld!=null && !tld.isApplicable(t))    continue;
              }
  
              r.add(t);
          }
          return r;
      }