code: function (modNames, comboPrefixes) {
              var comboMods = {},
                  packageUri,
                  runtime = this.runtime,
                  i = 0,
                  l = modNames.length,
                  modName, mod, packageInfo, type, typedCombos, mods,
                  tag, charset, packagePath,
                  packageName, group, fullpath;
  
              for (; i < l; ++i) {
                  modName = modNames[i];
                  mod = Utils.createModuleInfo(runtime, modName);
                  type = mod.getType();
                  fullpath = mod.getFullPath();
                  packageInfo = mod.getPackage();
                  packageName = packageInfo.getName();
                  charset = packageInfo.getCharset();
                  tag = packageInfo.getTag();
                  group = packageInfo.getGroup();
                  packagePath = packageInfo.getPrefixUriForCombo();
                  packageUri = packageInfo.getPackageUri();
  
                  var comboName = packageName;
                  // whether group packages can be combined (except default package and non-combo modules)
                  if ((mod.canBeCombined = packageInfo.isCombine() &&
                      S.startsWith(fullpath, packagePath)) && group) {
                      // combined package name
                      comboName = group + '_' + charset + '_' + groupTag;
  
                      var groupPrefixUri;
                      if (groupPrefixUri = comboPrefixes[comboName]) {
                          if (groupPrefixUri.isSameOriginAs(packageUri)) {
                              groupPrefixUri.setPath(getCommonPrefix(groupPrefixUri.getPath(),
                                  packageUri.getPath()));
                          } else {
                              comboName = packageName;
                              comboPrefixes[packageName] = packageUri;
                          }
                      } else {
                          comboPrefixes[comboName] = packageUri.clone();
                      }
                  } else {
                      comboPrefixes[packageName] = packageUri;
                  }
  
                  typedCombos = comboMods[type] = comboMods[type] || {};
                  if (!(mods = typedCombos[comboName])) {
                      mods = typedCombos[comboName] = [];
                      mods.charset = charset;
                      mods.tags = [tag]; // [package tag]
                  } else {
                      if (mods.tags.length == 1 && mods.tags[0] == tag) {
  
                      } else {
                          mods.tags.push(tag);
                      }
                  }
                  mods.push(mod);
              }
  
              return comboMods;
          }
docs: get combo mods for modNames