@Override
    public byte[] marshall(Map data) throws Exception {
        String dataAsString = mapper.writeValueAsString(data);
        return dataAsString.getBytes("UTF8"); //$NON-NLS-1$
    }
@see io.apiman.gateway.engine.io.IPayloadIO#marshall(java.lang.Object)
gateway/engine/core/src/main/java/io/apiman/gateway/engine/io/JsonPayloadIO.java