Why does BshScriptFactory require config interfaces?

Looking at BshScriptFactory in CVS, it doesn't accept null for the scriptInterfaces parameter like GroovyScriptFactory does. Why is this? BeanShell scripts are capable of providing their Java signatures themselves, i.e. reading .java files as scripts.

Should I create a patch for BshScriptFactory and BshScriptUtils, or will I have to write my own ScriptFactory that supports this?

Thanks
Ryan