<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def add(self, name, priority=3, comment="", parent=""):
 """Adds new item to the model. Name argument may contain (ref:) syntax, which will be stripped down as needed. :name: Name (with refs). :priority: Item's priority. :comment: Comment. :parent: Item's parent ("" for top-level item). """

        item = [name, priority, comment, False, []]
        data = self.data
        for c in self._split(parent):
            data = data[int(c) - 1][4]
        data.append(item)