code: function Image(src) {
    if (!(this instanceof Image)) {
      return new Image(src)
    }
  
    if (typeof src !== 'string') {
      throw new Error('param `src` must be a string')
    }
  
    var ret = reg.exec(src)
  
    if (!ret) {
      throw new Error('invalid param `src`')
    }
  
    this.src = src
    this.host = ret[1] || defaultHost
    this.version = ret[2] ? ret[2].slice(0, -1) : ''
    this.hash = ret[3]
    this.ext = ret[4]
  }
docs: Initialize `Image` with given `src`.
  
  @param {String} src
  @public