code: public void setNodeDirectory (final File value)
    {
      if (value != null && !value.isAbsolute ())
      {
        throw new IllegalArgumentException ("path is not absolute: " + value);
      }
      this.nodeDirectory = value;
    }
docs: Sets the absolute path to the output directory for the syntax tree files.
  
  @param value
  The absolute path to the output directory for the generated syntax
  tree files, may be <code>null</code> to use a sub directory in the
  output directory of the grammar file. If this directory does not
  exist yet, it is created. Note that this path should already include
  the desired package hierarchy because JTB will not append the
  required sub directories automatically.