code: private String findGemVersion(String gemName, String pathToGems) {
          String version = null;
          File maxVersionFile = findMaxVersionFile(gemName, pathToGems);
          if (maxVersionFile != null) {
              String fileName = maxVersionFile.getName();
              version = getVersionFromFileName(fileName, gemName);
          }
          return version;
      }
docs: in such cases, look for the relevant gem file in the cache with the highest version