anchor.diff:  library base64_codec;
   
   import 'dart:math';
  -import 'dart:typeddata';
  +import 'dart:typed_data';
   import 'dart:async';
   
   /**
  
positive.code:   /// LF seperator
    const int LF = 10;
  
  
    const _MAX_LENGTH= 64; // PEM line length
  
  
negative.code:             if (result >= 0) {
                  modulus = (modulus+1) % _BYTES_PER_ENCODED_BLOCK;
                  // https://groups.google.com/a/dartlang.org/d/msg/misc/6u9UNNLRjZw/YE9bV99lWyoJ
                  ibitWorkArea = ((ibitWorkArea << _BITS_PER_ENCODED_BYTE) & _MASK_INT) | result;
                  if (modulus == 0) {
                      buffer[outPos++] = ((ibitWorkArea >> 16) & 0xff);
                      buffer[outPos++] = ((ibitWorkArea >> 8) & 0xff);
  