code: def write_assoc(self, assoc):
          
          if assoc.get("header", False):
              return
  
          subj = assoc['subject']
  
          db, db_object_id = self._split_prefix(subj)
  
          rel = assoc['relation']
          qualifier = rel['id']
          if assoc['negated']:
              qualifier = 'NOT|' + qualifier
  
          goid = assoc['object']['id']
  
          ev = assoc['evidence']
  
          evidence = self.ecomap.coderef_to_ecoclass(ev['type'])
          withfrom = "|".join(ev['with_support_from'])
          reference = "|".join(ev['has_supporting_reference'])
  
          date = assoc['date']
          assigned_by = assoc['provided_by']
  
          annotation_properties = '' # TODO
          interacting_taxon_id = assoc['interacting_taxon']
          vals = [db,
                  db_object_id,
                  qualifier,
                  goid,
                  reference,
                  evidence,
                  withfrom,
                  interacting_taxon_id, # TODO
                  date,
                  assigned_by,
                  self._extension_expression(assoc['object_extensions']),
                  annotation_properties]
  
          self._write_row(vals)
docs: Write a single association to a line in the output file