try {
TextDocument doc = TextDocument.loadDocument(ResourceUtilities.getTestResourceAsStream(TEST_DOCUMENT));
// declare simple variable
VariableField simpleVariableField = Fields.createSimpleVariableField(doc, "test_simple_variable");
Assert.assertNotNull(simpleVariableField);
TextSpanElement newTextSpanElement = doc.newParagraph("Update Simple Variable Field:").newTextSpanElement();
simpleVariableField.updateField("simple variable content", newTextSpanElement);
FieldType fieldType = simpleVariableField.getFieldType();
Assert.assertNotNull(fieldType);
Assert.assertEquals(FieldType.SIMPLE_VARIABLE_FIELD, fieldType);