@Override
                public void writeTo(Output output, T message)
                        throws IOException
                {
                    if (primitive)
                        output.writeInt64(number, us.getLong(message, offset),
                                false);
                    else
                    {
                        Long value = (Long) us.getObject(message, offset);
                        if (value != null)
                            output.writeInt64(number, value.longValue(), false);
                    }
                }
Field factory via sun.misc.Unsafe.

@author David Yu
@created Jul 7, 2011
protostuff-runtime/src/main/java/io/protostuff/runtime/RuntimeUnsafeFieldFactory.java