@CanIgnoreReturnValue
    public Builder setPublicKey(RsaSsaPssPublicKey publicKey) {
      this.publicKey = publicKey;
      return this;
    }
Sets the public key, which includes the parameters.

<p>This is required.
java_src/src/main/java/com/google/crypto/tink/signature/RsaSsaPssPrivateKey.java