docs: @SuppressWarnings("unchecked")
      @Nonnull
      public final java.util.Optional<Style> getStyle(final String styleName) {
          final String styleRef = this.styles.get(styleName);
          Optional<Style> style;
          if (styleRef != null) {
              style = (Optional<Style>) this.styleParser
                      .loadStyle(getConfiguration(), this.httpRequestFactory, styleRef);
          } else {
              style = Optional.empty();
          }
          return or(style, this.configuration.getStyle(styleName));
      }