nl_tokens: Set the value of a property to the current value plus some amount .
pl_tokens: function ( keyName , increment ) { if ( Ember . isNone ( increment ) ) { increment = 1 ; } Ember . assert ( "Must pass a numeric value to incrementProperty" , ( ! isNaN ( parseFloat ( increment ) ) && isFinite ( increment ) ) ) ; set ( this , keyName , ( get ( this , keyName ) || 0 ) + increment ) ; return <mask> ( this , keyName ) ; }