@Override
  @NotNull
  public Collection<StructureViewTreeElement> getChildrenBase() {
    PsiClassOwner element = getElement();
    if (element == null) return Collections.emptyList();
    PsiClass[] classes = element.getClasses();
    PsiImplicitClass implicitClass = JavaImplicitClassUtil.getImplicitClassFor(element);
    if (implicitClass != null) {
      return JavaClassTreeElement.getClassChildren(implicitClass);
    }

    ArrayList<StructureViewTreeElement> result = new ArrayList<>();
    for (PsiClass aClass : classes) {
      result.add(new JavaClassTreeElement(aClass, false));
    }
    return result;

  }
@Override
  @NotNull
  public Collection<StructureViewTreeElement> getChildrenBase()