Fix already constant

rules/solid/src/Rector/ClassMethod/ChangeReadOnlyVariableWithDefaultValueToConstantRector.php

@@ -218,6 +218,11 @@ PHP
 
             /** @var Variable $variable */
             $variable = $readOnlyVariableAssign->var;
+            // already overriden
+            if (! $variable instanceof Variable) {
+                continue;
+            }
+
             $classConst = $this->createClassConst($variable, $readOnlyVariableAssign->expr);
 
             // replace $variable usage in the code with constant