code: public R visitCompilationUnit(CompilationUnitTree node, P p) {
          R r = scan(node.getPackageAnnotations(), p);
          r = scanAndReduce(node.getPackageName(), p, r);
          r = scanAndReduce(node.getImports(), p, r);
          r = scanAndReduce(node.getTypeDecls(), p, r);
          return r;
      }
docs: /* ***************************************************************************
  Visitor methods
  **************************************************************************