## DOCUMENT_TYPE

You must identify the currency of the amounts mentioned in the document.

If multiple currencies are present, use the one for the total amount.

Use the 3-letter ISO 4217 code when possible, and call the setStringIdentification function
with stringType=currency to complete the task.

If the currency is not identifiable, use the setFieldProblematic function to complete the task,
using "ABSENT" as problem type, and providing a description.

- [x] Function: setStringIdentification
- [x] Function: setFieldProblematic
- [x] Active