code: def build(self, parallel=True, debug=False, force=False,
                machine_readable=False):
          
          self.packer_cmd = self.packer.build
  
          self._add_opt('-parallel=true' if parallel else None)
          self._add_opt('-debug' if debug else None)
          self._add_opt('-force' if force else None)
          self._add_opt('-machine-readable' if machine_readable else None)
          self._append_base_arguments()
          self._add_opt(self.packerfile)
  
          return self.packer_cmd()
docs: Executes a `packer build`
  
          :param bool parallel: Run builders in parallel
          :param bool debug: Run in debug mode
          :param bool force: Force artifact output even if exists
          :param bool machine_readable: Make output machine-readable