Merge branch 'rishav/ddbec-v2/add-examples' of https://github.com/aws/aws-database-encryption-sdk-dynamodb into rishav/ddbec-v2/add-examples

Author: rishav-karanjit

DynamoDbEncryption/runtimes/java/src/main/java/software/amazon/cryptography/dbencryptionsdk/dynamodb/itemencryptor/internaldafny/legacy/InternalLegacyOverride.java

@@ -293,15 +293,21 @@ > convertActionsV1ToV2(Map<String, Set<EncryptionFlags>> v1Actions) {
   private static software.amazon.cryptools.dynamodbencryptionclientsdk2.encryption.EncryptionContext convertEncryptionContextV1ToV2(
     EncryptionContext v1Context
   ) {
-    return software.amazon.cryptools.dynamodbencryptionclientsdk2.encryption.EncryptionContext
+    final Map<String, software.amazon.awssdk.services.dynamodb.model.AttributeValue> v2AttributeValues = V1MapToV2Map(v1Context.getAttributeValues());
+    final software.amazon.cryptools.dynamodbencryptionclientsdk2.encryption.EncryptionContext.Builder builder = software.amazon.cryptools.dynamodbencryptionclientsdk2.encryption.EncryptionContext
       .builder()
       .tableName(v1Context.getTableName())
       .hashKeyName(v1Context.getHashKeyName())
       .rangeKeyName(v1Context.getRangeKeyName())
-      .attributeValues(V1MapToV2Map(v1Context.getAttributeValues()))
-      .developerContext(v1Context.getDeveloperContext())
-      .materialDescription(v1Context.getMaterialDescription())
-      .build();
+      .developerContext(v1Context.getDeveloperContext());
+
+    if (v1Context.getMaterialDescription() != null) {
+      builder.materialDescription(v1Context.getMaterialDescription());
+    }
+    if (v2AttributeValues != null) {
+      builder.attributeValues(v2AttributeValues);
+    }
+    return builder.build();
   }
 
   public static String ToNativeString(DafnySequence<? extends Character> s) {
@@ -510,6 +516,9 @@ public static software.amazon.awssdk.services.dynamodb.model.AttributeValue V1At
   > V1MapToV2Map(
     Map<String, com.amazonaws.services.dynamodbv2.model.AttributeValue> input
   ) {
+    if (input == null) {
+      return null;
+    }
     return input
       .entrySet()
       .stream()