function convertBody$5(buffer, headers) {
	if (typeof convert$5 !== 'function') {
		throw new Error('The package `encoding` must be installed to use the textConverted() function');
	}

	const ct = headers.get('content-type');
	let charset = 'utf-8';
	let res, str;

	// header
	if (ct) {
		res = /charset=([^;]*)/i.exec(ct);
	}

	// no charset in content type, peek at response body for at most 1024 bytes
	str = buffer.slice(0, 1024).toString();

	// html5
	if (!res && str) {
		res = /<meta.+?charset=(['"])(.+?)\1/i.exec(str);
	}

	// html4
	if (!res && str) {
		res = /<meta[\s]+?http-equiv=(['"])content-type\1[\s]+?content=(['"])(.+?)\2/i.exec(str);
		if (!res) {
			res = /<meta[\s]+?content=(['"])(.+?)\1[\s]+?http-equiv=(['"])content-type\3/i.exec(str);
			if (res) {
				res.pop(); // drop last quote
			}
		}

		if (res) {
			res = /charset=(.*)/i.exec(res.pop());
		}
	}

	// xml
	if (!res && str) {
		res = /<\?xml.+?encoding=(['"])(.+?)\1/i.exec(str);
	}

	// found charset
	if (res) {
		charset = res.pop();

		// prevent decode issues when sites use incorrect encoding
		// ref: https://hsivonen.fi/encoding-menu/
		if (charset === 'gb2312' || charset === 'gbk') {
			charset = 'gb18030';
		}
	}

	// turn raw buffers into a single utf-8 buffer
	return convert$5(buffer, 'UTF-8', charset).toString();
}
Detect buffer encoding and convert to target encoding
ref: http://www.w3.org/TR/2011/WD-html5-20110113/parsing.html#determining-the-character-encoding

@param   Buffer  buffer    Incoming buffer
@param   String  encoding  Target encoding
@return  String