nl_tokens: Use this function to find one viewmodel .
pl_tokens: function ( query , queryOptions , callback ) { if ( ! queryOptions ) { callback = <mask> ; query = { } ; queryOptions = { } ; } else if ( ! callback ) { callback = queryOptions ; queryOptions = { } ; } this . find ( query , queryOptions , function ( err , items ) { if ( err ) { return callback ( err ) ; } callback ( null , items [ 0 ] ) ; } ) ; }