docs: private static SSLContextBuilder loadKeyMaterial(SSLContextBuilder builder, File file, char[] ksp,
              char[] kp, PrivateKeyStrategy privateKeyStrategy) throws NoSuchAlgorithmException,
                      KeyStoreException, UnrecoverableKeyException, CertificateException, IOException {
          Args.notNull(file, "Keystore file"); //$NON-NLS-1$
          final KeyStore identityStore = KeyStore.getInstance(KeyStore.getDefaultType());
          final FileInputStream instream = new FileInputStream(file);
          try {
              identityStore.load(instream, ksp);
          } finally {
              instream.close();
          }
          return builder.loadKeyMaterial(identityStore, kp, privateKeyStrategy);
      }