Running out of memory using Infinispan after adding a small number of entities

While running a load test data builder for our application we ran out of memory very quickly. A simple test case (attached) was created to duplicate the issue. We found running the simple test case illustrates that Infinispan uses a large amount of heap space.

As a reference the same test was run using EHCache 2.2. Memory usage was much lower; we never ran out of heap space. Note that EHCache was used as a reference only, our goal is to go to production with Infinispan.