nl_tokens: Assert a configurable value .
pl_tokens: function assertRange ( name , val , max ) { assert . equal ( typeof val , 'number' , name + ' must be a number' ) assert ( ! isNaN ( val ) , 'number' , name + ' must be a number' ) if ( val > <mask> ) throw new RangeError ( name + ' must be lower than ' + max + ', but is ' + val ) else if ( val < 0 ) throw new RangeError ( name + ' must be greater than or equal to zero, but is ' + val ) else if ( val % 1 ) throw new RangeError ( name + ' must be an integer' ) }