code: public final Optional<? extends Style> getStyle(final String styleName) {
          final String styleRef = this.styles.get(styleName);
          if (styleRef != null) {
              return this.styleParser.loadStyle(this, this.clientHttpRequestFactory, styleRef);
          } else {
              return Optional.empty();
          }
  
  
      }
docs: Return the named style ot Optional.absent() if there is not a style with the given name.
  
  @param styleName the name of the style to look up