message: JavaScript: allow pre-population of asset data.
  Fixes
diff: @@ -82,7 +82,17 @@ Filament.postRun = function() {
  Filament.fetch = function(assets, onDone, onFetched) {
  var remainingAssets = assets.length;
  assets.forEach(function(name) {
  - const lower = name.toLowerCase();
  +
  + // Check if a buffer already exists in case the client wishes
  + // to provide its own data rather than using a HTTP request.
  + if (Filament.assets[name]) {
  + if (onFetched) {
  + onFetched(name);
  + }
  + if (--remainingAssets === 0 && onDone) {
  + onDone();
  + }
  + } else {
  fetch(name).then(function(response) {
  if (!response.ok) {
  throw new Error(name);
  @@ -97,5 +107,6 @@ Filament.fetch = function(assets, onDone, onFetched) {
  onDone();
  }
  });
  + }
  });
  };
  