def pre_process(control)
      Engine.logger.debug "Pre-processing #{control.file}"
      control.pre_processors.each do |processor|
        processor.process
      end
      Engine.logger.debug "Pre-processing complete"
    end
def pre_process(control)
      Engine.logger.debug "Pre-processing #{control.file}"
      control.pre_processors.each do |processor|
        processor.process
      end
      Engine.logger.debug "Pre-processing complete"
    end
Execute all preprocessors