How to use the cesium.RuntimeError function in cesium

if (hostname !== '') {
        // If hostname is set, then we have a UNC path
        // Pass the hostname through domainToUnicode just in case
        // it is an IDN using punycode encoding. We do not need to worry
        // about percent encoding because the URL parser will have
        // already taken care of that for us. Note that this only
        // causes IDNs with an appropriate `xn--` prefix to be decoded.
        return `\\\\${domainToUnicode(hostname)}${pathname}`;
    }

    // Otherwise, it's a local path that requires a drive letter
    const letter = pathname.codePointAt(1) | 0x20;
    const sep = pathname[2];
    if (letter < CHAR_LOWERCASE_A || letter > CHAR_LOWERCASE_Z ||   // a..z A..Z
        (sep !== ':')) {
        throw new RuntimeError('file URL must be absolute');
    }
    return pathname.slice(1);
}

function getPathFromURLWin32(url) {
    const hostname = url.hostname;
    let pathname = url.pathname;
    for (let n = 0; n < pathname.length; n++) {
        if (pathname[n] === '%') {
            const third = pathname.codePointAt(n + 2) | 0x20;
            if ((pathname[n + 1] === '2' && third === 102) || // 2f 2F /
                (pathname[n + 1] === '5' && third === 99)) {  // 5c 5C \
                throw new RuntimeError('file URL must not include encoded \\ or / characters');
            }
        }
    }
    pathname = pathname.replace(forwardSlashRegEx, '\\');
    pathname = decodeURIComponent(pathname);
    if (hostname !== '') {
        // If hostname is set, then we have a UNC path
        // Pass the hostname through domainToUnicode just in case
        // it is an IDN using punycode encoding. We do not need to worry
        // about percent encoding because the URL parser will have
        // already taken care of that for us. Note that this only
        // causes IDNs with an appropriate `xn--` prefix to be decoded.
        return `\\\\${domainToUnicode(hostname)}${pathname}`;
    }

    // Otherwise, it's a local path that requires a drive letter

it('throws an error if version is not 1 or 2', () => {
        const glb = Buffer.alloc(20);
        glb.write('glTF', 0);
        glb.writeUInt32LE(3, 4);

        let thrownError;
        try {
            parseGlb(glb);
        } catch (e) {
            thrownError = e;
        }
        expect(thrownError).toEqual(new RuntimeError('Binary glTF version is not 1 or 2'));
    });

it('throws an error if content format is not JSON', () => {
            const glb = Buffer.alloc(20);
            glb.write('glTF', 0);
            glb.writeUInt32LE(1, 4);
            glb.writeUInt32LE(20, 8);
            glb.writeUInt32LE(0, 12);
            glb.writeUInt32LE(1, 16);

            let thrownError;
            try {
                parseGlb(glb);
            } catch (e) {
                thrownError = e;
            }
            expect(thrownError).toEqual(new RuntimeError('Binary glTF scene format is not JSON'));
        });

function getPathFromURLPosix(url) {
    if (url.hostname !== '') {
        throw new RuntimeError('Invalid platform');
    }
    const pathname = url.pathname;
    for (let n = 0; n < pathname.length; n++) {
        if (pathname[n] === '%') {
            const third = pathname.codePointAt(n + 2) | 0x20;
            if (pathname[n + 1] === '2' && third === 102) {
                throw new RuntimeError('file URL must not include encoded \\ or / characters');
            }
        }
    }
    return decodeURIComponent(pathname);
}

function getPathFromURLPosix(url) {
    if (url.hostname !== '') {
        throw new RuntimeError('Invalid platform');
    }
    const pathname = url.pathname;
    for (let n = 0; n < pathname.length; n++) {
        if (pathname[n] === '%') {
            const third = pathname.codePointAt(n + 2) | 0x20;
            if (pathname[n + 1] === '2' && third === 102) {
                throw new RuntimeError('file URL must not include encoded \\ or / characters');
            }
        }
    }
    return decodeURIComponent(pathname);
}

function fileURLToPath(path) {
    Check.defined('path', path);

    if (typeof path === 'string') {
        path = new URL(path);
    }

    if (path.protocol !== 'file:') {
        throw new RuntimeError('Expected path.protocol to start with file:');
    }
    return isWindows ? getPathFromURLWin32(path) : getPathFromURLPosix(path);
}