code: public static byte[] toByteArrayFst(final Object obj, final ClassLoader classLoader) {
          if (obj == null) {
              return null;
          }
          ClassLoader oldClassLoader = Thread.currentThread().getContextClassLoader();
          if (classLoader != null) {
              Thread.currentThread().setContextClassLoader(classLoader);
          }
          try {
              FSTConfiguration conf = fstConf.get();
              conf.setClassLoader(classLoader != null ? classLoader : oldClassLoader);
              return conf.asByteArray(obj);
          } catch (Exception e) {
              throw e instanceof SerializationException ? (SerializationException) e
                      : new SerializationException(e);
          } finally {
              Thread.currentThread().setContextClassLoader(oldClassLoader);
          }
      }
docs: Serialize an object to byte array, with a custom class loader.
  
  <p>
  This method uses FST lib.
  </p>
  
  @param obj
  @param classLoader
  @return
  @since 0.6.0