code: public final DecryptResponse decrypt(String name, ByteString ciphertext) {
  
      DecryptRequest request =
          DecryptRequest.newBuilder().setName(name).setCiphertext(ciphertext).build();
      return decrypt(request);
    }
docs: Decrypts data that was protected by
  [Encrypt][google.cloud.kms.v1.KeyManagementService.Encrypt]. The
  [CryptoKey.purpose][google.cloud.kms.v1.CryptoKey.purpose] must be
  [ENCRYPT_DECRYPT][google.cloud.kms.v1.CryptoKey.CryptoKeyPurpose.ENCRYPT_DECRYPT].
  
  <p>Sample code:
  
  <pre><code>
  try (KeyManagementServiceClient keyManagementServiceClient = KeyManagementServiceClient.create()) {
  CryptoKeyName name = CryptoKeyName.of("[PROJECT]", "[LOCATION]", "[KEY_RING]", "[CRYPTO_KEY]");
  ByteString ciphertext = ByteString.copyFromUtf8("");
  DecryptResponse response = keyManagementServiceClient.decrypt(name.toString(), ciphertext);
  }
  </code></pre>
  
  @param name Required. The resource name of the [CryptoKey][google.cloud.kms.v1.CryptoKey] to
  use for decryption. The server will choose the appropriate version.
  @param ciphertext Required. The encrypted data originally returned in
  [EncryptResponse.ciphertext][google.cloud.kms.v1.EncryptResponse.ciphertext].
  @throws com.google.api.gax.rpc.ApiException if the remote call fails