code: function Resolver(domains, arbiters, exts, npmTree, builtIns, serverModules) {
    this.finder = makeFinder(exts);
    this.npmResolve = makeNpmResolver(domains.npm);
    this.domains = domains;
    this.arbiters = arbiters;
    this.exts = exts;
    this.npmTree = npmTree;
    this.builtIns = builtIns;
    this.serverModules = serverModules;
  }
docs: Resolver constructor
  @[in] domains - {name : path} object
  @[in] arbiters - list of requirable arbiters
  @[in] exts - list of registered extensions