### Question:
DynamoDbEncryptor implements DynamoDbEncryptionClient { String getSignatureFieldName() { return signatureFieldName; } protected  DynamoDbEncryptor(EncryptionMaterialsProvider provider, String descriptionBase); protected  DynamoDbEncryptor(EncryptionMaterialsProvider provider); static Builder builder(); @Override Map<String, AttributeValue> encryptRecord(Map<String, AttributeValue> record,
                                                     DynamoDbEncryptionConfiguration configuration); @Override Map<String, AttributeValue> decryptRecord(Map<String, AttributeValue> record,
                                                     DynamoDbEncryptionConfiguration configuration);  }### Answer:
@Test(expectedExceptions = DynamoDbEncryptionException.class) public void signedOnlyNoSignature() { Map<String, AttributeValue> encryptedAttributes = EncryptionTestHelper.encryptAllFieldsExcept(encryptor, attribs, context, attribs.keySet()); assertThat(encryptedAttributes, AttrMatcher.invert(attribs)); encryptedAttributes.remove(encryptor.getSignatureFieldName()); EncryptionTestHelper.decryptAllFieldsExcept(encryptor, encryptedAttributes, context, attribs.keySet()); }