nl_tokens: Return a new ArrayBuffer by concatenating an array of ArrayBuffers .
pl_tokens: function concatArrayBuffers ( buffers : ArrayBuffer [ ] ) : ArrayBuffer { var totalBytes = buffers . map ( b => b . byteLength ) . reduce ( ( a , b ) => a + b , 0 ) ; var output = new Uint8Array ( totalBytes ) ; var position = 0 ; buffers . forEach ( buf => { output . set ( <mask> Uint8Array ( buf ) , position ) ; position += buf . byteLength ; } ) ; return output . buffer ; }