message: Add better names for Snapshot Iterators
diff: @@ -470,19 +470,19 @@ class SnapshotDatasetOp : public UnaryDatasetOpKernel {
  case WRITER:
  iterator_ = absl::make_unique<SnapshotWriterIterator>(
  SnapshotWriterIterator::Params{
  - dataset(), strings::StrCat(prefix(), "Impl")},
  + dataset(), strings::StrCat(prefix(), "WriterImpl")},
  hash_dir_);
  break;
  case READER:
  iterator_ = absl::make_unique<SnapshotReaderIterator>(
  SnapshotReaderIterator::Params{
  - dataset(), strings::StrCat(prefix(), "Impl")},
  + dataset(), strings::StrCat(prefix(), "ReaderImpl")},
  hash_dir_, metadata);
  break;
  case PASSTHROUGH:
  iterator_ = absl::make_unique<SnapshotPassthroughIterator>(
  SnapshotPassthroughIterator::Params{
  - dataset(), strings::StrCat(prefix(), "Impl")});
  + dataset(), strings::StrCat(prefix(), "PassthroughImpl")});
  break;
  }
  TF_RETURN_IF_ERROR(iterator_->Initialize(ctx));
  