def resume
        if @paused_block
          halted, error = callcc do |block|
            @resume_block = block
            @paused_block.call
          end
          
          @resume_block = @paused_block = nil
          
          raise error if error
          !halted
        else
          true
        end
      end
def resume
        if @paused_block
          halted, error = callcc do |block|
            @resume_block = block
            @paused_block.call
          end
          
          @resume_block = @paused_block = nil
          
          raise error if error
          !halted
        else
          true
        end
      end
Resumes the execution of a previously paused callback execution.  Once
 the paused callbacks complete, the current execution will continue.