How to use the notion.utils.add_signed_prefix_as_needed function in notion

if prop["type"] in ["multi_select"]:
            val = [v.strip() for v in val[0][0].split(",")] if val else []
        if prop["type"] in ["person"]:
            val = (
                [self._client.get_user(item[1][0][1]) for item in val if item[0] == "‣"]
                if val
                else []
            )
        if prop["type"] in ["email", "phone_number", "url"]:
            val = val[0][0] if val else ""
        if prop["type"] in ["date"]:
            val = NotionDate.from_notion(val)
        if prop["type"] in ["file"]:
            val = (
                [
                    add_signed_prefix_as_needed(item[1][0][1], client=self._client)
                    for item in val
                    if item[0] != ","
                ]
                if val
                else []
            )
        if prop["type"] in ["checkbox"]:
            val = val[0][0] == "Yes" if val else False
        if prop["type"] in ["relation"]:
            val = (
                [
                    self._client.get_block(item[1][0][1])
                    for item in val
                    if item[0] == "‣"
                ]
                if val

view.set("collection_id", self._parent._collection.id)
        view_ids = self._parent.get(CollectionViewBlockViews.child_list_key, [])
        view_ids.append(view.id)
        self._parent.set(CollectionViewBlockViews.child_list_key, view_ids)

        # At this point, the view does not see to be completely initialized yet.
        # Hack: wait a bit before e.g. setting a query.
        time.sleep(3)
        return view


class CollectionViewPageBlock(CollectionViewBlock):

    icon = field_map(
        "format.page_icon",
        api_to_python=add_signed_prefix_as_needed,
        python_to_api=remove_signed_prefix_as_needed,
    )

    _type = "collection_view_page"


class FramerBlock(EmbedBlock):

    _type = "framer"


class TweetBlock(EmbedBlock):

    _type = "tweet"