anchor.diff:     * running the command `git diff <blob> <blob>`.
      */
     BlobDiff getBlobDiff(String srcBlob, String dstBlob) {
  -    ProcessResult result = _run(['diff', srcBlob, dstBlob]);
  +    ProcessResult result = _run(['diff', '-U0', srcBlob, dstBlob]);
       List<String> diffResults = LineSplitter.split(result.stdout).toList();
       return new BlobDiff._(diffResults);
     }
  
positive.code:   CommitDelta getCommitDiff(String srcCommit, String dstCommit) {
      // Consider --find-renames instead of --no-renames if rename information is
      // desired.
      ProcessResult result = _run(['diff', '--raw', '--no-abbrev', '--no-renames',
          '-z', srcCommit, dstCommit]);
      return new CommitDelta._(this, result.stdout);
    }
  
  
negative.code: }
  
  /**
   * Representation of a single diff hunk.
   */
  class DiffHunk {
  