JavacTask task = (JavacTask)javac.getTask(null, null, null, null, null, compilationUnits);
Trees trees = Trees.instance(task);
CompilationUnitTree toplevel = task.parse().iterator().next();
ClassTree classTree = (ClassTree)toplevel.getTypeDecls().get(0);
List<? extends Tree> annotations = classTree.getModifiers().getAnnotations();
Tree tree1 = annotations.get(0);
Tree tree2 = annotations.get(1);
long pos = trees.getSourcePositions().getStartPosition(toplevel, tree1);
if (pos != 0)
throw new AssertionError(String.format("Start pos for %s is incorrect (%s)!",
tree1, pos));
pos = trees.getSourcePositions().getEndPosition(toplevel, tree1);