code: def build(self, lv2_uri):
          
          try:
              plugin = self._plugins[lv2_uri]
          except KeyError:
              raise Lv2EffectBuilderError(
                  "Lv2EffectBuilder not contains metadata information about the plugin '{}'. \n"
                  "Try re-scan the installed plugins using the reload method::\n"
                  "   >>> lv2_effect_builder.reload(lv2_effect_builder.lv2_plugins_data())".format(lv2_uri))
  
          return Lv2Effect(plugin)
docs: Returns a new :class:`.Lv2Effect` by the valid lv2_uri
  
          :param string lv2_uri:
          :return Lv2Effect: Effect created