unshiftChunk(chunk) {
		const oldIdx = this.chunks.indexOf(chunk);
		if (oldIdx > 0) {
			this.chunks.splice(oldIdx, 1);
			this.chunks.unshift(chunk);
		} else if (oldIdx < 0) {
			this.chunks.unshift(chunk);
			return true;
		}
		return false;
	}
Performs an unshift of a specific chunk
@param {Chunk} chunk chunk being unshifted
@returns {boolean} returns true if attempted chunk shift is accepted