@Test
void testPrepareSetVariableAssertionMissingBase64Value() throws DocumentParseException {

    Element setVariableAssertion = document.createElement(SET_VARIABLE);
    document.appendChild(setVariableAssertion);
    Element variableToSet = document.createElement(VARIABLE_TO_SET);
    variableToSet.setAttribute(PolicyEntityBuilder.STRING_VALUE, "my.var");
    setVariableAssertion.appendChild(variableToSet);
    String prefix = "prefix";
    setVariableAssertionBuilder.buildAssertionElement(setVariableAssertion, policyBuilderContext);
    Element nameElement = getSingleElement(setVariableAssertion, VARIABLE_TO_SET);
    assertEquals("my.var", nameElement.getAttribute(PolicyEntityBuilder.STRING_VALUE));
    Element expressionElement = getSingleChildElement(setVariableAssertion, BASE_64_EXPRESSION, true);
    assertNull(expressionElement);
}