@Nullable
    private PsiReferenceExpression getReferenceFromImplicitNullCheckExpression(PsiExpression expression) {
      expression = PsiUtil.skipParenthesizedExprDown(expression);
      PsiReferenceExpression checked = getReferenceFromBooleanCall(expression);
      if (checked == null) {
        checked = getReferenceFromOrChain(expression);
      }
      return checked;
    }
@Nullable
    private PsiReferenceExpression getReferenceFromImplicitNullCheckExpression(PsiExpression expression)