code: private String processKey(String key) {
          AssertUtils.assertNotNull(key, "Key cannot be null");
  
          String result = null;
  
          if (this.isCaseSensitive() == false) {
              result = key.toLowerCase(Locale.ENGLISH);
          } else {
              result = key;
          }
  
          return result;
      }
docs: Utility function.
  Processes key and converts it's case if required
  
  @param key Key
  @return Processed Key