private static boolean isQualifierUnnecessary(PsiElement qualifier, PsiClass containingClass) {
    if (qualifier instanceof PsiReferenceExpression reference && reference.resolve() instanceof PsiClass &&
        reference.getQualifier() == null && PsiTreeUtil.isContextAncestor(containingClass, qualifier, false)) {
      return true;
    }
    return qualifier instanceof PsiThisExpression thisExpression && thisExpression.getQualifier() == null;
  }
private static boolean isQualifierUnnecessary(PsiElement qualifier, PsiClass containingClass)