code: function parseHotkey(hotkey, options) {
    const byKey = options && options.byKey
    const ret = {}
  
    // Special case to handle the `+` key since we use it as a separator.
    hotkey = hotkey.replace('++', '+add')
    const values = hotkey.split('+')
    const { length } = values
  
    // Ensure that all the modifiers are set to false unless the hotkey has them.
    for (const k in MODIFIERS) {
      ret[MODIFIERS[k]] = false
    }
  
    for (let value of values) {
      const optional = value.endsWith('?')
  
      if (optional) {
        value = value.slice(0, -1)
      }
  
      const name = toKeyName(value)
      const modifier = MODIFIERS[name]
  
      if (length === 1 || !modifier) {
        if (byKey) {
          ret.key = name
        } else {
          ret.which = toKeyCode(value)
        }
      }
  
      if (modifier) {
        ret[modifier] = optional ? null : true
      }
    }
  
    return ret
  }
docs: Parse.