public void addAdditionalSymbolClass(FXGSymbolClass symbolClass){
  if (additionalSymbolClasses == null)   additionalSymbolClasses=new ArrayList<FXGSymbolClass>();
  additionalSymbolClasses.add(symbolClass);
}

public void addAdditionalSymbolClass ( FXGSymbolClass symbolClass ) { if ( additionalSymbolClasses == null ) additionalSymbolClasses = new ArrayList < FXGSymbolClass > ( ) ; additionalSymbolClasses . add ( symbolClass ) ; }
an fxg node may have child nodes that also require a symbol class mapping that will be included along with the parent symbol for the compilation unit .
