@Override
  public boolean equals(Object o) {
    if (this == o) {
      return true;
    }

    if (!(o instanceof FileIndex)) {
      return false;
    }

    FileIndex that = (FileIndex) o;

    return new EqualsBuilder()
        .append(getFileName(), that.getFileName())
        .append(getBlobs(), that.getBlobs())
        .append(fileMetadata, that.fileMetadata)
        .append(getChecksum(), that.getChecksum())
        .isEquals();
  }
Checksum of the file for verifying integrity.
samza-core/src/main/java/org/apache/samza/storage/blobstore/index/FileIndex.java