private Map<Module, List<VirtualFile>> buildModuleToFilesMap(
     final List<VirtualFile> filesToCompile) {
   if (myChunk.getNodes().size() == 1) {
     return Collections.singletonMap(
         myChunk.getNodes().iterator().next(), Collections.unmodifiableList(filesToCompile));
   }
   return CompilerUtil.buildModuleToFilesMap(myCompileContext, filesToCompile);
 }