Add check if resolved type is set

Author: sandrokeil

src/Type/ReferenceType.php

@@ -93,19 +93,23 @@ public function resolvedType(): ?TypeSet
 
     public function setIsRequired(bool $required): void
     {
-        foreach ($this->resolvedType as $type) {
-            if ($type instanceof RequiredAware) {
-                $type->setIsRequired($required);
+        if ($this->resolvedType !== null) {
+            foreach ($this->resolvedType as $type) {
+                if ($type instanceof RequiredAware) {
+                    $type->setIsRequired($required);
+                }
             }
         }
         $this->isRequired = $required;
     }
 
     public function setNullable(bool $nullable): void
     {
-        foreach ($this->resolvedType as $type) {
-            if ($type instanceof NullableAware) {
-                $type->setNullable($nullable);
+        if ($this->resolvedType !== null) {
+            foreach ($this->resolvedType as $type) {
+                if ($type instanceof NullableAware) {
+                    $type->setNullable($nullable);
+                }
             }
         }
         $this->nullable = $nullable;