code: public static PointSymbolizer pointSymbolizerFromRule( Rule rule ) {
          List<Symbolizer> symbolizers = rule.symbolizers();
          PointSymbolizer pointSymbolizer = null;
          for( Symbolizer symbolizer : symbolizers ) {
              if (symbolizer instanceof PointSymbolizer) {
                  pointSymbolizer = (PointSymbolizer) symbolizer;
                  break;
              }
          }
          if (pointSymbolizer == null) {
              throw new IllegalArgumentException();
          }
          return pointSymbolizer;
      }
docs: Get the {@link PointSymbolizer} from the given rule.
  
  @param rule the rule to check for symbolizers.
  @return the first symbolizer found.