code: private static String join(String typeMapping, String mapping) {
  		return MULTIPLE_SLASHES.matcher(typeMapping.concat("/").concat(mapping)).replaceAll("/");
  	}
docs: Joins the given mappings making sure exactly one slash.
  
  @param typeMapping must not be {@literal null} or empty.
  @param mapping must not be {@literal null} or empty.
  @return