Method appendLeft

benchmark/data.js:306–316

(index, content)

		return this;
	}
	appendLeft(index, content) {
		if (typeof content !== 'string') throw new TypeError('inserted content must be a string');
		this._split(index);
		const chunk = this.byEnd[index];
		if (chunk) {
			chunk.appendLeft(content);
		} else {
			this.intro += content;
		}
		return this;
	}
	appendRight(index, content) {
		if (typeof content !== 'string') throw new TypeError('inserted content must be a string');
		this._split(index);