You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: sell_nft.rs
    path of file: ./repos/joystream/runtime-modules/content/src/tests/nft
    
    the code of the file until where you have to start completion: #![cfg(test)]
use crate::tests::fixtures::*;
use crate::tests::mock::*;
use crate::*;
use frame_support::{assert_err, assert_noop, assert_ok};

#[test]
fn sell_nft() {
    with_default_mock_builder(|| {
        // Run to block one to see emitted events
        run_to_block(1);

        let video_id = NextVideoId::<Test>::get();

        create_initial_storage_buckets_helper();
        increase_account_balance_helper(DEFAULT_MEMBER_ACCOUNT_ID, INITIAL_BALANCE)
    
fn sell_nft_video_does_not_exist() {
    with_default_mock_builder(|| {
        // Run to block one to see emitted events
        run_to_block(1);

        let video_id = NextVideoId::<Test>::get();

        // Make an attempt to sell nft which corresponding video does not exist yet
        let sell_nft_result = Content::sell_nft(
            Origin::signed(DEFAULT_MEMBER_ACCOUNT_ID),
            video_id,
            ContentActor::Member(DEFAULT_MEMBER_ID),
            DEFAULT_NFT_PRICE,
        );

        // Failure checked
        assert_err!(sell_nft_result, Error::<Test>::VideoDoesNotExist);
    })
}