code: public String getLocationStr() {
          if (locationStr == null && location != null) {
              locationStr = location.toString();
          }
          return locationStr;
      }
docs: Get the module location as a string, i.e. {@code getReference().location().toString()}. Returns null for
  modules that do not have a location.
  
  @return The module location as a string, i.e. {@code getReference().location().toString()}. Returns null for
  modules that do not have a location.