anchor.diff:            if (!bestEquality1.isEmpty) {
               diffs[pointer - 1].text = bestEquality1;
             } else {
  -            diffs.removeRange(pointer - 1, 1);
  +            diffs.removeAt(pointer - 1);
               pointer--;
             }
             diffs[pointer].text = bestEdit;
             if (!bestEquality2.isEmpty) {
               diffs[pointer + 1].text = bestEquality2;
             } else {
  -            diffs.removeRange(pointer + 1, 1);
  +            diffs.removeAt(pointer + 1);
               pointer--;
             }
           }
  
positive.code:             patch.length2 += diff_text.length;
              start2 += diff_text.length;
              patch.diffs.add(bigpatch.diffs[0]);
              bigpatch.diffs.removeRange(0, 1);
              empty = false;
            } else if (diff_type == DIFF_DELETE && patch.diffs.length == 1
                && patch.diffs[0].operation == DIFF_EQUAL
  
negative.code:       }
        Patch bigpatch = patches[x];
        // Remove the big old patch.
        patches.removeAt(x--);
        int start1 = bigpatch.start1;
        int start2 = bigpatch.start2;
        String precontext = '';
  