code: public static PCMContainer loadPCMContainer(String filename) throws IOException {
  
          // Define a file representing a PCM to load
          File pcmFile = new File(filename);
  
          // Create a loader that can handle the file format
          PCMLoader loader = new KMFJSONLoader();
  
          // Load the file
          // A loader may return multiple PCM containers depending on the input format
          // A PCM container encapsulates a PCM and its associated metadata
          List<PCMContainer> pcmContainers = loader.load(pcmFile);
  
          PCMContainer pcmContainer = pcmContainers.get(0);
          return pcmContainer;
      }
docs: A helper method to get a PCMContainer (limited in a sense we only retrieve the 1st element of containers)
  @param filename
  @return
  @throws IOException