@Test
public void testNot() throws ParserException {

    final RootNode root = parser.parse("not(eq(username,123))");
    assertThat(root).isNotNull();
    assertThat(root.getChildren().size()).isEqualTo(1);
    final LogicalNode and = (LogicalNode) root.getChildren().get(0);
    assertThat(and.getName()).isEqualTo("not");
    assertThat(and.getType()).isEqualTo(LogicalNode.Type.NOT);
    assertThat(and.getChildren().size()).isEqualTo(1);
}