code: public static UriTemplate templateFor(@Nullable String mapping) {
  
  		Assert.hasText(mapping, "Mapping must not be null or empty!");
  
  		return CACHE.computeIfAbsent(mapping, UriTemplate::new);
  	}
docs: Returns the the {@link UriTemplate} for the given mapping.
  
  @param mapping must not be {@literal null} or empty.
  @return