code: private TableName snapshotExists(String snapshotName,
        List<SnapshotDescription> snapshotDescriptions) {
      if (snapshotDescriptions != null) {
        Optional<SnapshotDescription> descriptor =
            snapshotDescriptions.stream()
                .filter(desc -> desc.getName().equals(snapshotName))
                .findFirst();
        return descriptor.isPresent() ? descriptor.get().getTableName() : null;
      }
      return null;
    }
docs: To check Snapshot exists or not.
  
  @param snapshotName
  @param snapshotDescriptions
  @return