static prefix(s, prefix) {
		const str = Template.asString(s).trim();
		if (!str) return "";
		const ind = str[0] === "\n" ? "" : prefix;
		return ind + str.replace(/\n([^\n])/g, `\n${prefix}$1`);
	}
@param {string|string[]} s string to create prefix for
@param {string} prefix prefix to compose
@returns {string} returns new prefix string