docs: def save_dependencies(self, instance, schema):
          """Save data: and list:data: references as parents."""
          def add_dependency(value):
              """Add parent Data dependency."""
              try:
                  DataDependency.objects.update_or_create(
                      parent=Data.objects.get(pk=value),
                      child=self,
                      defaults={'kind': DataDependency.KIND_IO},
                  )
              except Data.DoesNotExist:
                  pass
  
          for field_schema, fields in iterate_fields(instance, schema):
              name = field_schema['name']
              value = fields[name]
  
              if field_schema.get('type', '').startswith('data:'):
                  add_dependency(value)
              elif field_schema.get('type', '').startswith('list:data:'):
                  for data in value:
                      add_dependency(data)