Updated rule to private in visitor

Author: daria-trusca-solid

lib/src/lints/avoid_unnecessary_setstate/visitors/avoid_unnecessary_set_state_visitor.dart

@@ -38,12 +38,12 @@ class AvoidUnnecessarySetStateVisitor extends SimpleAstVisitor<void> {
   ];
 
   /// The rule associated with this visitor.
-  final AvoidUnnecessarySetStateRule rule;
+  final AvoidUnnecessarySetStateRule _rule;
 
   final _setStateInvocations = <MethodInvocation>[];
 
   /// Creates an instance of [AvoidUnnecessarySetStateVisitor].
-  AvoidUnnecessarySetStateVisitor(this.rule);
+  AvoidUnnecessarySetStateVisitor(this._rule);
 
   @override
   void visitClassDeclaration(ClassDeclaration node) {
@@ -61,8 +61,9 @@ class AvoidUnnecessarySetStateVisitor extends SimpleAstVisitor<void> {
     }
 
     final methods = body.members.whereType<MethodDeclaration>();
-    final classMethodsNames =
-        methods.map((declaration) => declaration.name.lexeme).toSet();
+    final classMethodsNames = methods
+        .map((declaration) => declaration.name.lexeme)
+        .toSet();
     final methodBodies = methods.map((declaration) => declaration.body).toSet();
 
     final checkedMethods = methods.where(_isMethodChecked);
@@ -95,7 +96,7 @@ class AvoidUnnecessarySetStateVisitor extends SimpleAstVisitor<void> {
       );
 
       for (final element in _setStateInvocations) {
-        rule.reportAtNode(element);
+        _rule.reportAtNode(element);
       }
     }
   }
@@ -119,8 +120,10 @@ class AvoidUnnecessarySetStateVisitor extends SimpleAstVisitor<void> {
       return true;
     }
 
-    final visitor =
-        AvoidUnnecessarySetStateMethodVisitor(classMethodsNames, bodies);
+    final visitor = AvoidUnnecessarySetStateMethodVisitor(
+      classMethodsNames,
+      bodies,
+    );
     declaration.visitChildren(visitor);
 
     final hasSetState = visitor.setStateInvocations.isNotEmpty;