SoftIndexFileStoreStressTest is broken

SoftIndexFileStoreStressTest fails as SoftIndexfileStore doesn't handle AdvancedCacheLoader.process

java.lang.UnsupportedOperationException: Should call processEntries!
at org.infinispan.persistence.spi.AdvancedCacheLoader.process(AdvancedCacheLoader.java:54)
at org.infinispan.persistence.sifs.SoftIndexFileStoreStressTest.testMethod(SoftIndexFileStoreStressTest.java:111)