code: @Override
  	public <R, D> R accept(DuzztREVisitor<R, D> visitor, D data) {
  		return visitor.visit(this, data);
  	}
docs: /*
  (non-Javadoc)
  @see com.github.misberner.duzzt.re.DuzztRegExp#accept(com.github.misberner.duzzt.re.DuzztREVisitor, java.lang.Object)