code: public int read_nil() throws OtpErlangDecodeException {
          int arity = 0;
          final int tag = read1skip_version();
  
          switch (tag) {
          case OtpExternal.nilTag:
              arity = 0;
              break;
  
          default:
              throw new OtpErlangDecodeException("Not valid nil tag: " + tag);
          }
  
          return arity;
      }
docs: Read an empty list from the stream.
  
  @return zero (the arity of the list).
  
  @exception OtpErlangDecodeException
  if the next term in the stream is not an empty list.