private void checkExpression(PsiVariable variable, PsiExpression expression) {
        if (!(expression instanceof PsiReferenceExpression refExpr)) {
          return;
        }
        final PsiExpression qualifier = refExpr.getQualifierExpression();
        if ((qualifier == null || qualifier instanceof PsiQualifiedExpression || variable.hasModifierProperty(PsiModifier.STATIC)) 
            && refExpr.isReferenceTo(variable)) {
          holder.registerProblem(refExpr,
                                 JavaBundle.message("assignment.to.declared.variable.problem.descriptor", variable.getName()),
                                 LocalQuickFix.notNullElements(createRemoveAssignmentFix(refExpr)));
        }
      }
private void checkExpression(PsiVariable variable, PsiExpression expression)