code: public boolean verifySignature(byte[] publicKey, byte[] message, byte[] signature) {
      if (publicKey == null || publicKey.length != 32) {
        throw new IllegalArgumentException("Invalid public key!");
      }
  
      if (message == null || signature == null || signature.length != 64) {
        return false;
      }
  
      return provider.verifySignature(publicKey, message, signature);
    }
docs: Verify a Curve25519 signature.
  
  @param publicKey The Curve25519 public key the signature belongs to.
  @param message The message that was signed.
  @param signature The signature to verify.
  @return true if valid, false if not.