Method append

benchmark/data.js:301–305

(content)

		this.sourcemapLocations.add(char);
	}
	append(content) {
		if (typeof content !== 'string') throw new TypeError('outro content must be a string');
		this.outro += content;
		return this;
	}
	appendLeft(index, content) {
		if (typeof content !== 'string') throw new TypeError('inserted content must be a string');
		this._split(index);