Fixed optable npe.

Author: And1sS

extra/modules/optable-targeting/src/main/java/org/prebid/server/hooks/modules/optable/targeting/v1/core/BidResponseEnricher.java

@@ -8,6 +8,7 @@
 import com.iab.openrtb.response.BidResponse;
 import com.iab.openrtb.response.SeatBid;
 import org.apache.commons.collections4.CollectionUtils;
+import org.apache.commons.lang3.StringUtils;
 import org.prebid.server.exception.InvalidRequestException;
 import org.prebid.server.hooks.execution.v1.auction.AuctionResponsePayloadImpl;
 import org.prebid.server.hooks.modules.optable.targeting.model.openrtb.Audience;
@@ -70,14 +71,15 @@ private ObjectNode targetingToObjectNode(List<Audience> targeting) {
 
         for (Audience audience : targeting) {
             final List<AudienceId> ids = audience.getIds();
-            if (CollectionUtils.isEmpty(ids)) {
+            final String keyspace = audience.getKeyspace();
+            if (CollectionUtils.isEmpty(ids) || StringUtils.isEmpty(keyspace)) {
                 continue;
             }
 
             final String joinedIds = ids.stream()
                     .map(AudienceId::getId)
                     .collect(Collectors.joining(","));
-            node.putIfAbsent(audience.getKeyspace(), TextNode.valueOf(joinedIds));
+            node.putIfAbsent(keyspace, TextNode.valueOf(joinedIds));
         }
 
         return node;

extra/modules/optable-targeting/src/test/java/org/prebid/server/hooks/modules/optable/targeting/v1/core/BidResponseEnricherTest.java

@@ -1,6 +1,7 @@
 package org.prebid.server.hooks.modules.optable.targeting.v1.core;
 
 import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.iab.openrtb.response.BidResponse;
 import org.junit.jupiter.api.Test;
 import org.prebid.server.hooks.execution.v1.auction.AuctionResponsePayloadImpl;
 import org.prebid.server.hooks.modules.optable.targeting.model.openrtb.Audience;
@@ -10,10 +11,30 @@
 
 import java.util.List;
 
+import static java.util.Collections.singletonList;
 import static org.assertj.core.api.Assertions.assertThat;
 
 public class BidResponseEnricherTest extends BaseOptableTest {
 
+    @Test
+    public void shouldSkipEmptyKeyspaceWhileEnrichingBidResponse() {
+        // given
+        final BidResponse bidResponse = givenBidResponse();
+        final AuctionResponsePayload auctionResponsePayload = AuctionResponsePayloadImpl.of(bidResponse);
+        final List<Audience> targeting = singletonList(new Audience(
+                "provider",
+                List.of(new AudienceId("audienceId"), new AudienceId("audienceId2")),
+                null,
+                1));
+        final BidResponseEnricher enricher = BidResponseEnricher.of(targeting, mapper, jsonMerger);
+
+        // when
+        final AuctionResponsePayload result = enricher.apply(auctionResponsePayload);
+
+        // then
+        assertThat(result.bidResponse()).isEqualTo(bidResponse);
+    }
+
     @Test
     public void shouldEnrichBidResponseByTargetingKeywords() {
         // given