private SecurityModule securityModule() {
    return securityModuleService
        .getByName(securityModuleName)
        .orElseThrow(() -> new RuntimeException("Security Module not found: " + securityModuleName))
        .get();
  }
Returns data directory used by Besu. Visible as it is accessed by other subcommands.

@return Path representing data directory.
app/src/main/java/org/hyperledger/besu/cli/BesuCommand.java