Function updateMounted

src/useFieldArray.ts:482–487

(name: InternalFieldName, value: boolean)

        control._options.shouldUnregister || shouldUnregister
      );
      const updateMounted = (name: InternalFieldName, value: boolean) => {
        const field: Field = get(control._fields, name);
        if (field && field._f) {
          field._f.mount = value;
        }
      };

      if (_actioned.current && shouldKeepFieldArrayValues) {
        control._subjects.state.next({