nl_tokens: from ethereumjs - util
pl_tokens: function stripZeros ( aInput ) { var a = aInput ; // eslint-disable-line var first = a [ 0 ] ; // eslint-disable-line while ( a . length > 0 && <mask> . toString ( ) === '0' ) { a = a . slice ( 1 ) ; first = a [ 0 ] ; } return a ; }