@Test
    public void imported_fields_only_supported_for_simple_expressions() throws ParseException {
        // TODO we should probably handle this case specially and give a better exception message
        var documents = createDocs();
        try {
            // Nested field access is NOT considered a simple expression.
            evaluate("test.my_imported_field.foo", documents.get(0));
            fail("Expected exception");
        } catch (IllegalArgumentException e) {
            assertEquals("Field 'my_imported_field' not found in document type 'test'",
                         Exceptions.toMessageString(e));
        }
    }
@author Simon Thoresen Hult
@author bratseth
document/src/test/java/com/yahoo/document/select/DocumentSelectorTestCase.java