text: module.exports = function math (options) {
    this.add({role: 'math', cmd: 'sum'}, (msg, respond) => {
      var sum = msg.left + msg.right
      respond(null, {answer: sum})
    })
  
    this.add({role: 'math', cmd: 'product'}, (msg, respond) => {
      var product = msg.left * msg.right
      respond(null, {answer: product})
    })
  }
  