问如何使用JavaParser在新行上添加批注？

EN

public static String annotate() {
    String classString = new StringJoiner("\n")
            .add("class A {")
            .add("")
            .add("  @ExistingAnnotation")
            .add("  private int i;")
            .add("")
            .add("}")
            .toString();

    CompilationUnit cu = StaticJavaParser.parse(classString);
    LexicalPreservingPrinter.setup(cu);

    cu.findFirst(FieldDeclaration.class).get()
            .addAnnotation("Annotation")
            .addAnnotation(Nonnull.class)
            .addMarkerAnnotation("MarkerAnnotation");

    return LexicalPreservingPrinter.print(cu);
}

import javax.annotation.Nonnull;

class A {

  @ExistingAnnotation @Annotation() @Nonnull() @MarkerAnnotation
  private int i;

}

  @ExistingAnnotation
  @Annotation()
  @Nonnull()
  @MarkerAnnotation
  private int i;