adding null check before for loop

Author: Ayushman-Gaur

tools/flagd-core/src/main/java/dev/openfeature/contrib/tools/flagd/core/FlagdCore.java

@@ -269,8 +269,11 @@ private <T> ProviderEvaluation<T> resolve(Class<T> type, String key, EvaluationC
 
     private static ImmutableMetadata getFlagMetadata(Map<String, Object> currentFlagSetMetadata, FeatureFlag flag) {
         ImmutableMetadata.ImmutableMetadataBuilder metadataBuilder = ImmutableMetadata.builder();
-        for (Map.Entry<String, Object> entry : currentFlagSetMetadata.entrySet()) {
-            addEntryToMetadataBuilder(metadataBuilder, entry.getKey(), entry.getValue());
+
+        if (currentFlagSetMetadata != null) {
+            for (Map.Entry<String, Object> entry : currentFlagSetMetadata.entrySet()) {
+                addEntryToMetadataBuilder(metadataBuilder, entry.getKey(), entry.getValue());
+            }
         }
 
         if (flag != null && flag.getMetadata() != null) {