code: def _process(self, plugin, instance=None):
          
  
          self.processing["nextOrder"] = plugin.order
  
          try:
              result = pyblish.plugin.process(plugin, self.context, instance)
  
          except Exception as e:
              raise Exception("Unknown error: %s" % e)
  
          else:
              # Make note of the order at which the
              # potential error error occured.
              has_error = result["error"] is not None
              if has_error:
                  self.processing["ordersWithError"].add(plugin.order)
  
          return result
docs: Produce `result` from `plugin` and `instance`
  
          :func:`process` shares state with :func:`_iterator` such that
          an instance/plugin pair can be fetched and processed in isolation.
  
          Arguments:
              plugin (pyblish.api.Plugin): Produce result using plug-in
              instance (optional, pyblish.api.Instance): Process this instance,
                  if no instance is provided, context is processed.