docs: public void setReturnValue(MethodDescriptor methodDesc, TypeQualifierValue<?> tqv, TypeQualifierAnnotation tqa) {
          Map<TypeQualifierValue<?>, TypeQualifierAnnotation> map = returnValueMap.get(methodDesc);
          if (map == null) {
              map = new HashMap<>();
              returnValueMap.put(methodDesc, map);
          }
          map.put(tqv, tqa);
  
          if (DEBUG) {
              System.out.println("tqdb: " + methodDesc + " for " + tqv + " ==> " + tqa);
          }
      }