Adding methods to class and use them in other groovy code -

i'm new groovy. have class i'm adding methods using metaclass. here code have parser.groovy:

privateclass.metaclass.convertddttomap { obj,filelocation ->  } 

where privateclass class coming jar. in other file named hack.groovy have following code:

class hack extends privateclass { //.. code convertddttomap(param,param) } 

when run hack.groovy, exception method convertddttomap not there.

however parser.groovy in same classpath , gets compiled. not adding method.

where i'm making mistake?

parser.groovy being compiled doing nothing, code there needs called. example using new parser().run()