Javassist has known limits.
With this feature you have the possibility to implement your own solution using the library that you prefer.

By default, the library used to generate the source is Javassist, but if you want to use a custom solution follow this step:

• create a package with name com.googlecode.jmapper.generation.impl
• create a generator class that implement the interface ICodeGenerator
• the resulting class must implement the interface IMapper

For more clarification, look at the javassist implementation.

in short time will be released several implementations for the most known bytecode libraries