public class CacheConfiguration
{
    public static final String DEFAULT_CACHE_NAME = "DefaultCacheName";
    @Produces
    @ApplicationScoped
    public EmbeddedCacheManager defaultCacheManager()
    {
        final GlobalConfigurationBuilder globalConfigurationBuilder =
            new GlobalConfigurationBuilder().nonClusteredDefault()
                .jmx()
                .defaultCacheName( DEFAULT_CACHE_NAME );

        ConfigurationBuilderHolder configurationBuilderHolder =
            new ConfigurationBuilderHolder( Thread.currentThread()
                .getContextClassLoader(), globalConfigurationBuilder );

        createCacheConfig( configurationBuilderHolder );

        configurationBuilderHolder.validate();
        return new DefaultCacheManager( configurationBuilderHolder, true );
    }

    private void createCacheConfig( final ConfigurationBuilderHolder aConfigurationBuilderHolder )
    {
        aConfigurationBuilderHolder.newConfigurationBuilder( DEFAULT_CACHE_NAME )
            .transaction()
            .transactionMode( TransactionMode.TRANSACTIONAL )
            .lockingMode( LockingMode.OPTIMISTIC )
            .memory()
            .whenFull( EvictionStrategy.NONE )
            .locking()
            .isolationLevel( IsolationLevel.READ_COMMITTED );
    }
} 

@ApplicationScoped
public class TestBean{
    @Inject
    private EmbeddedCacheManager cacheManager;

    public void testMethod(){
        String name = "SomeName";
        addConfiguration( name );
        cacheManager.getCache( name ).values()
            .stream()
            //some filtering
            .filter( obj -> obj.toString().length()>10)
            // throws NPE
            .findFirst();
    }

    private void addConfiguration( final String aCacheName )
    {
        if( cacheManager.getCacheConfiguration( aCacheName ) == null )
        {
            cacheManager.defineConfiguration( aCacheName, cacheManager.getDefaultCacheConfiguration() );
        }
    }
}

 Caused by: java.util.concurrent.CompletionException: java.lang.NullPointerException: item1 is null
     at org.infinispan:ispn-14.0//org.infinispan.util.concurrent.CompletionStages.join(CompletionStages.java:87)
     at org.infinispan:ispn-14.0//org.infinispan.stream.impl.AbstractCacheStream.performPublisherOperation(AbstractCacheStream.java:200)
     at org.infinispan:ispn-14.0//org.infinispan.stream.impl.DistributedCacheStream.findAny(DistributedCacheStream.java:327)
     at org.infinispan:ispn-14.0//org.infinispan.stream.impl.DistributedCacheStream.findFirst(DistributedCacheStream.java:321)
     at org.infinispan:ispn-14.0//org.infinispan.util.AbstractDelegatingCacheStream.findFirst(AbstractDelegatingCacheStream.java:315)
     at deployment.XXX.war//com.xxx.yyy.xxx.TestBean.testMethod
     ... 49 more
 Caused by: java.lang.NullPointerException: item1 is null
     at java.base/java.util.Objects.requireNonNull(Objects.java:235)
     at org.infinispan:ispn-14.0//io.reactivex.rxjava3.core.Flowable.just(Flowable.java:3067)
     at java.base/java.util.concurrent.CompletableFuture.biApply(CompletableFuture.java:1311)
     at java.base/java.util.concurrent.CompletableFuture.biApplyStage(CompletableFuture.java:1329)
     at java.base/java.util.concurrent.CompletableFuture.thenCombine(CompletableFuture.java:2210)
     at java.base/java.util.concurrent.CompletableFuture.thenCombine(CompletableFuture.java:144)
     at org.infinispan:ispn-14.0//org.infinispan.reactive.publisher.impl.LocalClusterPublisherManagerImpl.entryReduction(LocalClusterPublisherManagerImpl.java:124)
     at org.infinispan:ispn-14.0//org.infinispan.stream.impl.AbstractCacheStream.performPublisherOperation(AbstractCacheStream.java:197)