nl_tokens: 逐个分片计算并检查 ETag 是否一致
pl_tokens: function ( index ) { if ( index < PartCount ) { var Part = PartList [ index ] ; getChunkETag ( Part . PartNumber , function ( err , chunk ) { if ( chunk && chunk . ETag === Part . ETag && chunk . Size === <mask> . Size ) { next ( index + 1 ) ; } else { callback ( null , false ) ; } } ) ; } else { callback ( null , true ) ; } }