code: function _print (template, values, options) {
    return template.replace(/\$([\w.]+)/g, function (original, key) {
      const keys = key.split('.')
      let value = values[keys.shift()]
      while (keys.length && value !== undefined) {
        const k = keys.shift()
        value = k ? value[k] : value + '.'
      }
  
      if (value !== undefined) {
        if (!isString(value)) {
          return format(value, options)
        } else {
          return value
        }
      }
  
      return original
    }
    )
  }
docs: Interpolate values into a string template.
  @param {string} template
  @param {Object} values
  @param {number | Object} [options]
  @returns {string} Interpolated string
  @private