code: function asyncStartLoadPartwayThrough(stepState) {
      return function(resolve, reject) {
        var loader = stepState.loader;
        var name = stepState.moduleName;
        var step = stepState.step;
  
        if (loader.modules[name])
          throw new TypeError('"' + name + '" already exists in the module table');
  
        // adjusted to pick up existing loads
        var existingLoad;
        for (var i = 0, l = loader.loads.length; i < l; i++) {
          if (loader.loads[i].name == name) {
            existingLoad = loader.loads[i];
  
            if (step == 'translate' && !existingLoad.source) {
              existingLoad.address = stepState.moduleAddress;
              proceedToTranslate(loader, existingLoad, Promise.resolve(stepState.moduleSource));
            }
  
            // a primary load -> use that existing linkset if it is for the direct load here
            // otherwise create a new linkset unit
            if (existingLoad.linkSets.length && existingLoad.linkSets[0].loads[0].name == existingLoad.name)
              return existingLoad.linkSets[0].done.then(function() {
                resolve(existingLoad);
              });
          }
        }
  
        var load = existingLoad || createLoad(name);
  
        load.metadata = stepState.moduleMetadata;
  
        var linkSet = createLinkSet(loader, load);
  
        loader.loads.push(load);
  
        resolve(linkSet.done);
  
        if (step == 'locate')
          proceedToLocate(loader, load);
  
        else if (step == 'fetch')
          proceedToFetch(loader, load, Promise.resolve(stepState.moduleAddress));
  
        else {
          console.assert(step == 'translate', 'translate step');
          load.address = stepState.moduleAddress;
          proceedToTranslate(loader, load, Promise.resolve(stepState.moduleSource));
        }
      }
    }
docs: 15.2.4.7 PromiseOfStartLoadPartwayThrough absorbed into calling functions 15.2.4.7.1