code: public String hackInv(ANamedTypeDeclIR type) {
          ATypeDeclIR tDecl = (ATypeDeclIR) type.parent();
  
          if (tDecl.getInv() != null) {
              AFuncDeclIR invFunc = (AFuncDeclIR) tDecl.getInv();
              StringBuilder sb = new StringBuilder();
              sb.append("inv ");
              sb.append(invFunc.getFormalParams().get(0).getPattern().toString());
              sb.append(" == ");
              sb.append(invFunc.getName());
              sb.append("(");
              sb.append("&");
              sb.append(invFunc.getFormalParams().get(0).getPattern().toString());
              sb.append(")");
              return sb.toString();
          }
          return "";
      }
docs: FIXME Unhack invariant extraction for named types