OutOfMemory exception during bulk downloads

Question

I'm intermittently getting OOM exceptions in the java 13.0.20 api during the download to file. I'm confused why it'd be consuming memory at that point, but regardless, are there any practical ideas for avoiding these other than serializing all requests?

java.lang.OutOfMemoryError: Java heap space
    at java.util.ArrayList.iterator(ArrayList.java:1029)
    at jdk.internal.net.http.HttpClientImpl$SelectorManager.run(HttpClientImpl.java:1262)

java.io.IOException: selector manager closed
    at jdk.internal.net.http.HttpClientImpl$SelectorManager.selectorClosedException(HttpClientImpl.java:1126)
    at jdk.internal.net.http.HttpClientImpl.sendAsync(HttpClientImpl.java:1005)
    at jdk.internal.net.http.HttpClientImpl.sendAsync(HttpClientImpl.java:985)
    at jdk.internal.net.http.HttpClientImpl.sendAsync(HttpClientImpl.java:977)
    at jdk.internal.net.http.HttpClientFacade.sendAsync(HttpClientFacade.java:143)
    at org.apache.cxf.transport.http.HttpClientHTTPConduit$HttpClientWrappedOutputStream.setProtocolHeaders(HttpClientHTTPConduit.java:410)
    at org.apache.cxf.transport.http.HTTPConduit$WrappedOutputStream.handleHeadersTrustCaching(HTTPConduit.java:1351)
    at org.apache.cxf.transport.http.HTTPConduit$WrappedOutputStream.onFirstWrite(HTTPConduit.java:1331)
    at org.apache.cxf.io.AbstractWrappedOutputStream.write(AbstractWrappedOutputStream.java:47)
    at org.apache.cxf.io.AbstractThresholdOutputStream.write(AbstractThresholdOutputStream.java:69)
    at org.apache.cxf.transport.http.HTTPConduit$WrappedOutputStream.close(HTTPConduit.java:1383)
    at org.apache.cxf.io.AbstractWrappedOutputStream.close(AbstractWrappedOutputStream.java:77)
    at org.apache.cxf.io.AbstractWrappedOutputStream.close(AbstractWrappedOutputStream.java:77)
    at org.apache.cxf.io.AbstractThresholdOutputStream.close(AbstractThresholdOutputStream.java:102)
    at org.apache.cxf.transport.AbstractConduit.close(AbstractConduit.java:56)
    at org.apache.cxf.transport.http.HTTPConduit.close(HTTPConduit.java:695)
    at org.apache.cxf.interceptor.MessageSenderInterceptor$MessageSenderEndingInterceptor.handleMessage(MessageSenderInterceptor.java:63)
    at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:307)
    at org.apache.cxf.jaxrs.client.AbstractClient.doRunInterceptorChain(AbstractClient.java:710)
    at org.apache.cxf.jaxrs.client.WebClient.prepareAsyncClient(WebClient.java:1000)
    at org.apache.cxf.jaxrs.client.WebClient.doInvokeAsync(WebClient.java:963)
    at org.apache.cxf.jaxrs.client.WebClient.doInvokeAsyncCallback(WebClient.java:952)
    at org.apache.cxf.jaxrs.client.AsyncInvokerImpl.method(AsyncInvokerImpl.java:211)
    at org.apache.cxf.jaxrs.client.AsyncInvokerImpl.post(AsyncInvokerImpl.java:94)
    at com.microsoft.bingads.internal.restful.RestfulServiceClient.processRequestAsync(RestfulServiceClient.java:345)
    at com.microsoft.bingads.internal.restful.BulkService.sendRequestAsync(BulkService.java:83)
    at com.microsoft.bingads.internal.restful.BulkService.downloadCampaignsByAccountIdsAsync(BulkService.java:102)
    at com.microsoft.bingads.v13.bulk.BulkServiceManager.submitDownloadAsync(BulkServiceManager.java:560)
    at com.microsoft.bingads.v13.bulk.BulkServiceManager.downloadFileAsyncImpl(BulkServiceManager.java:483)
    at com.microsoft.bingads.v13.bulk.BulkServiceManager.downloadFileAsync(BulkServiceManager.java:473)
    at com.microsoft.bingads.v13.bulk.BulkServiceManager.downloadFileAsync(BulkServiceManager.java:456)