def METHOD_NAME(self, indexes):
    """
    Builds a dict mapping db name to item type to a list of ids.
    Returns:
        QMimeData
    """
    items = {self.item_from_index(ind): None for ind in indexes}  # NOTE: this avoids dupes and keeps order
    d = {}
    for item in items:
        parent_item = item.parent_item
        db_row = self.db_row(parent_item)
        parent_type = parent_item.item_type
        master_key = ";;".join([str(db_row), parent_type])
        d.setdefault(master_key, []).append(item.child_number())
    data = json.dumps(d)
    mime = QMimeData()
    mime.setText(data)
    return mime