code: public static AiScene importFile(String filename, 
              Set<AiPostProcessSteps> postProcessing, AiIOSystem<?> ioSystem) 
                    throws IOException {
          
          return aiImportFile(filename, AiPostProcessSteps.toRawValue(
                  postProcessing), ioSystem);
      }
docs: Imports a file via assimp.
  
  @param filename the file to import
  @param postProcessing post processing flags
  @param ioSystem ioSystem to load files, or null for default
  @return the loaded scene, or null if an error occurred
  @throws IOException if an error occurs