code: private String convertFileNameToBaseClassName(String filename) {
          if (filename.endsWith("_.java")) {
              return substringBeforeLast(filename, "_.java") + BASE_SUFFIX_;
          } else {
              return substringBeforeLast(filename, ".java") + BASE_SUFFIX;
          }
      }
docs: add Base to a given java filename it is used for transparently subclassing generated classes