code: public char[] getPublicKey() throws GeneralSecurityException, IOException {
          if (publicKey != null) {
              return publicKey;
          }
  
          KeyPair keys = getKeyPair();
          EdDSAPublicKey pubKey = (EdDSAPublicKey) keys.getPublic();
          byte[] pubBytes = pubKey.getAbyte();
  
          return encode(this.type, pubBytes);
      }
docs: @return the encoded public key for this NKey
  
  @throws GeneralSecurityException if there is an encryption problem
  @throws IOException              if there is a problem encoding the public
  key