how to add composite key as a sync configuration for a table

[Manish061]

Hi,
My question is regarding - initSync function. When we pass the table configuration, how to pass composite key for the idName parameter.

syclib.initSync([{ tableName: 'Moods' },
{ tableName: 'Sampletable', idName: 'composite_key' }], db,
{user: userInfo}, sync_url, (data) => {}, null, null, null);

Thanks.