code: function Vultr(apiKey) {
    this.version = 'v1';
    this.endpoint = 'https://api.vultr.com/' + this.version + '/';
    this.apiKey = (apiKey ? apiKey : config.vultr.apiKey);
  
    this.account = new account(this);
    this.dns = new dns(this);
    this.os = new os(this);
    this.iso = new iso(this);
    this.backup = new backup(this);
    this.plans = new plans(this);
    this.regions = new regions(this);
    this.server = new server(this);
    this.snapshot = new snapshot(this);
    this.sshkey = new sshkey(this);
    this.startupscript = new startupscript(this);
  }
docs: Vultr instance constructor
  @prototype
  @class  Vultr