I am studying the code of correlate_access_code_bb_impl.cc for understanding its working. I see that the block is derive from "block" class of gr as written in correlate_access_code_bb_ts.h file
class DIGITAL_API correlate_access_code_bb_ts : virtual public block
I read earlier that blocks derived from "block"/"gr::block" should implement forecast() method, but I did not see any implementation of forecast() in code of correlate_access_code_bb_impl.cc.