How to use the @pixi/utils.log2 function in @pixi/utils

getIndexBuffer(size)
    {
        // 12 indices is enough for 2 quads
        const roundedP2 = nextPow2(Math.ceil(size / 12));
        const roundedSizeIndex = log2(roundedP2);
        const roundedSize = roundedP2 * 12;

        if (this._iBuffers.length <= roundedSizeIndex)
        {
            this._iBuffers.length = roundedSizeIndex + 1;
        }

        let buffer = this._iBuffers[roundedSizeIndex];

        if (!buffer)
        {
            this._iBuffers[roundedSizeIndex] = buffer = new Uint16Array(roundedSize);
        }

        return buffer;
    }

getAttributeBuffer(size)
    {
        // 8 vertices is enough for 2 quads
        const roundedP2 = nextPow2(Math.ceil(size / 8));
        const roundedSizeIndex = log2(roundedP2);
        const roundedSize = roundedP2 * 8;

        if (this._aBuffers.length <= roundedSizeIndex)
        {
            this._iBuffers.length = roundedSizeIndex + 1;
        }

        let buffer = this._aBuffers[roundedSize];

        if (!buffer)
        {
            this._aBuffers[roundedSize] = buffer = new ViewableBuffer(roundedSize * this.vertexSize * 4);
        }

        return buffer;
    }

getAttributeBuffer(size)
    {
        // 8 vertices is enough for 2 quads
        const roundedP2 = nextPow2(Math.ceil(size / 8));
        const roundedSizeIndex = log2(roundedP2);
        const roundedSize = roundedP2 * 8;

        if (this._aBuffers.length <= roundedSizeIndex)
        {
            this._iBuffers.length = roundedSizeIndex + 1;
        }

        let buffer = this._aBuffers[roundedSize];

        if (!buffer)
        {
            this._aBuffers[roundedSize] = buffer = new ViewableBuffer(roundedSize * this.vertexSize * 4);
        }

        return buffer;
    }

getIndexBuffer(size)
    {
        // 12 indices is enough for 2 quads
        const roundedP2 = nextPow2(Math.ceil(size / 12));
        const roundedSizeIndex = log2(roundedP2);
        const roundedSize = roundedP2 * 12;

        if (this._iBuffers.length <= roundedSizeIndex)
        {
            this._iBuffers.length = roundedSizeIndex + 1;
        }

        let buffer = this._iBuffers[roundedSizeIndex];

        if (!buffer)
        {
            this._iBuffers[roundedSizeIndex] = buffer = new Uint16Array(roundedSize);
        }

        return buffer;
    }