@BeforeClass
    public static void forceLoadingOfSerializableClasses() {
        com.yahoo.searchlib.aggregation.ForceLoad.forceLoad();
        com.yahoo.searchlib.expression.ForceLoad.forceLoad();
    }
Tests serialization compatibility across Java and C++. The comparison is performed by comparing serialized Java
object graphs with the content of specific binary files. C++ unit tests serializes
identical data structures into these files.
Note: This test relies heavily on proper implementation of {@link Object#equals(Object)}!
searchlib/src/test/java/com/yahoo/searchlib/aggregation/GroupingSerializationTest.java