because the NULL values are seen to be the same journal_line_id
Suggestion
We could add journal_id or journal_number to the relations test. However, there still might be a case where there is a journal with more than one row in the model that has a NULL value in journal_line_id
There are instances where there are rows in the xero__general_ledger model that have a NULL value in the journal_line_id column.
This causes the test:
dbt_utils_unique_combination_of_columns_xerogeneral_ledger_journal_line_idsource_relation
because the NULL values are seen to be the same journal_line_id
Suggestion
We could add journal_id or journal_number to the relations test. However, there still might be a case where there is a journal with more than one row in the model that has a NULL value in journal_line_id