// move the cursor to the beginning of the tail, containing: offset to the
// meta block index, version and magic
fin.seek(fileLength - Magic.size() - Version.size() - Long.SIZE
/ Byte.SIZE);
long offsetIndexMeta = fin.readLong();
version = new Version(fin);
Magic.readAndVerify(fin);
if (!version.compatibleWith(BCFile.API_VERSION)) {
throw new RuntimeException("Incompatible BCFile fileBCFileVersion.");
}