nl_tokens: Compute the diff between the 2 objects based on the hash value
pl_tokens: function diffRecords ( localRecords , newRecords ) { var recordsDiff = { } ; _ . each ( newRecords , function ( record , uid ) { if ( localRecords [ uid ] ) { if ( localRecords [ uid ] . hash !== record . <mask> ) { record . op = "update" ; recordsDiff [ uid ] = record ; } } else { record . op = "update" ; recordsDiff [ uid ] = record ; } } ) ; _ . each ( localRecords , function ( record , uid ) { if ( ! newRecords [ uid ] ) { record . op = "delete" ; recordsDiff [ uid ] = record ; } } ) ; return recordsDiff ; }