Customize how drools checks if an object is already asserted in its working memory

If two objects A and B are asserted, where A != B, but A.eqals(B) is true, then drools adds both of them to working memory, creating two fact handles. Behaviour is based on using org.drools.util.IdentityMap as identityMap in Reteoo workingMemoryImpl

My request is to add another behaviour and customizable which to use.
Drools should assert an object B, if there is not already an object A in working memory where A.equals(B) is true. (Basically this behaviour is achieved by using HashMap instead of IdentityMap)

Customization should be possible via setting properties on workingMemory creation. In JSR94 it would be a property for createRuleSession:

HashMap properties = new HashMap();
properties.put("org.drools.objectequality", "equals");
//properties.put("org.drools.objectequality", "identity"); //default value
StatefulRuleSession session = (StatefulRuleSession)ruleRuntime.createRuleSession(executionSetName, properties, RuleRuntime.STATEFUL_SESSION_TYPE);

• Currently, properties are used to set global variables. So "org.drools.objectequality" would yield unknown global error.