private ClassTree classTree(String classBody) {
   CompilationUnitTree compilationUnitTree = (CompilationUnitTree) p.parse(classBody);
   SemanticModel.createFor(compilationUnitTree, Lists.<File>newArrayList());
   return (ClassTree) compilationUnitTree.types().get(0);
 }
 private CompilationUnitTree createTree(String code) {
   CompilationUnitTree compilationUnitTree = (CompilationUnitTree) p.parse(code);
   SemanticModel.createFor(compilationUnitTree, Lists.<File>newArrayList());
   return compilationUnitTree;
 }