def save_m2m(self, obj, data, using_transactions, dry_run):
if not using_transactions and dry_run:<EOL><INDENT>pass<EOL><DEDENT>else:<EOL><INDENT>for field in self.get_import_fields():<EOL><INDENT>if not isinstance(field.widget, widgets.ManyToManyWidget):<EOL><INDENT>continue<EOL><DEDENT>self.import_field(field, obj, data, True)<EOL><DEDENT><DEDENT>
Saves m2m fields.

Model instance need to have a primary key value before
a many-to-many relationship can be used.