nl_tokens: https : // github . com / ftlabs / js - abbreviate / blob / fa709e5f139e7770a71827b1893f22418097fbda / index . js#L95 - L106
pl_tokens: function stringifyError ( value ) { var err = { // These properties are implemented as magical getters and don't show up in for in stack : value . stack , message : value . message , name : value . name } ; for ( var i in value ) { if ( Object . prototype . hasOwnProperty . call ( value , i ) ) { err [ i ] = value [ i ] ; } } return <mask> ; }