docs: public Writer writeTo(final Writer out) throws IOException {
          if (this.out!=null) {
              // StackOverflow prevention
              return NullWriter.DEFAULT;
          }
          try {
              this.out = createWriter(out);
              run();
              return out;
          } finally {
              if (this.out!=null) {
                  this.out.flush();
              }
              this.out = null;
          }
      }