public KeyPair loadKeyPair(final File nodePrivateKeyFile) {
    return KeyPairUtil.loadKeyPair(resolveNodePrivateKeyFile(nodePrivateKeyFile));
  }
Load key pair from private key. Visible to be accessed by subcommands.

@param nodePrivateKeyFile File containing private key
@return KeyPair loaded from private key file
app/src/main/java/org/hyperledger/besu/cli/BesuCommand.java