title: Mule ESB - NetSuite Upsert with Custom Fields
body: <p>I'm trying to upsert Journal Lines with Mule ESB, using the NetSuite connector.
  In our setup there are a lot of custom fields, some are required.
   There is a Journal Entry with several lines, which has to be posted to NS, using an upsert operation, but I'm stuck with custom fields.</p>
  
  <p>Here is what I tried so far:</p>
  
  <ol>
  <li>created a JournalEntry object, and passed it to the NetSuite component. Failed, as it is not a map, and there is no Upsert Object operation.</li>
  <li>passed this object to DataMapper. The CustomFields are not mapped, also the resulting map is an unreadable mess. </li>
  <li>created a map of the fields, where custom fields were a maps inside the map, got JAXB errors.</li>
  </ol>
  
  <p>Unfortunately the documentation is not mentioning custom fields at all.
  Anyone can tell me a working approach?</p>