def METHOD_NAME(self, instance):
    invalid = []
    container = instance.data["instance_node"]
    self.log.info(f"Validating tyFlow object for {container}")
    selection_list = instance.data["members"]
    bool_list = []
    for sel in selection_list:
        obj = sel.baseobject
        anim_names = rt.GetSubAnimNames(obj)
        for anim_name in anim_names:
            # get all the names of the related tyFlow nodes
            sub_anim = rt.GetSubAnim(obj, anim_name)
            # check if there is export particle operator
            boolean = rt.IsProperty(sub_anim, "Export_Particles")
            bool_list.append(str(boolean))
        # if the export_particles property is not there
        # it means there is not a "Export Particle" operator
        if "True" not in bool_list:
            self.log.error("Operator 'Export Particles' not found!")
            invalid.append(sel)
    return invalid