@AccessesPartialKey
  static EcdsaPublicKey toEcdsaPublicKey(com.google.crypto.tink.jwt.JwtEcdsaPublicKey publicKey)
      throws GeneralSecurityException {
    EcdsaParameters ecdsaParameters =
        EcdsaParameters.builder()
            .setSignatureEncoding(EcdsaParameters.SignatureEncoding.IEEE_P1363)
            .setCurveType(getCurveType(publicKey.getParameters()))
            .setHashType(getHash(publicKey.getParameters()))
            .build();
    return EcdsaPublicKey.builder()
        .setParameters(ecdsaParameters)
        .setPublicPoint(publicKey.getPublicPoint())
        .build();
  }
This key manager produces new instances of {@code JwtEcdsaVerify}. It doesn't support key
generation.
java_src/src/main/java/com/google/crypto/tink/jwt/JwtEcdsaVerifyKeyManager.java