code: def render_koji(self):
          
          phase = 'prebuild_plugins'
          plugin = 'koji'
          if not self.pt.has_plugin_conf(phase, plugin):
              return
  
          if self.user_params.yum_repourls.value:
              self.pt.remove_plugin(phase, plugin, 'there is a yum repo user parameter')
          elif not self.pt.set_plugin_arg_valid(phase, plugin, "target",
                                                self.user_params.koji_target.value):
              self.pt.remove_plugin(phase, plugin, 'no koji target supplied in user parameters')
docs: if there is yum repo in user params, don't pick stuff from koji