nl_tokens: Collects all of the values of the given property and returns their sum
pl_tokens: function ( property , root , start , end ) { var values = this . extractValues ( property , root ) , length = values . length , <mask> = 0 , i ; start = start || 0 ; end = ( end || end === 0 ) ? end : length - 1 ; for ( i = start ; i <= end ; i ++ ) { sum += values [ i ] ; } return sum ; }