question: private void printRawError ( int pos , String msg ) { if ( source == null || pos == Position . NOPOS ) { printRawLines ( errWriter , "error: " + msg ) ; } else { int line = source . getLineNumber ( pos ) ; JavaFileObject file = source . getFile ( ) ; if ( file != null ) printRawLines ( errWriter , file . getName ( ) + ":" + line + ": " + msg ) ; printErrLine ( pos , errWriter ) ; } errWriter . flush ( ) ; }
target:  print an error or warning message: