lib/utils/error.js
exports.nil = new Error('#NULL!');
exports.div0 = new Error('#DIV/0!');
exports.value = new Error('#VALUE!');
exports.ref = new Error('#REF!');
exports.name = new Error('#NAME?');
exports.num = new Error('#NUM!');
exports.na = new Error('#N/A');
exports.error = new Error('#ERROR!');
exports.data = new Error('#GETTING_DATA');