nl_tokens: / * @see http : // www . w3 . org / TR / PNG - Chunks . html
pl_tokens: function filterNone ( line , colorsPerPixel , prevLine ) { /*var result = new Uint8Array(line.length + 1);
      result[0] = 0;
      result.set(line, 1);*/ var result = Array . <mask> ( [ ] , line ) ; result . unshift ( 0 ) ; return result ; }