inline fun <reified E : Any> restList(...){
    ...

cEditItem {
    item = editedItem
    saveElement = { 
        props.updateItem(
            Item(it, editedItem.id, editedItem.version)
        ) 
    }
    key = editedItem.id
}

val addStudentMutation = 
    useMutation<HTTPResult, Any, StudentId, Any>(
        mutationFn = { studentId ->
fetch(
    "${Config.lessonsPath}/${AddStudentToLesson.path}",
    jso {
        method = "POST"
        headers = json("Content-Type" to "application/json")
        body = Json.encodeToString(AddStudentToLesson(
            props.lesson.id,
            studentId,
            props.lesson.version))
    }
)       }