code: public static void put(String extension, String contentType) {
          if (extension != null && extension.length() != 0
                  && contentType != null && contentType.length() != 0) {
  
              contentTypes.put(extension, contentType);
          }
      }
docs: <p> Associates the specified extension and content type </p>
  
  @param extension   the extension
  @param contentType the content type associated with the extension