@Test
public void testFilterExpression() {

    String inputExpression = "[ {x:1, y:2}, {x:2, y:3} ][ x=1 ]";
    BaseNode filterBase = parse( inputExpression );
    assertThat( filterBase, is( instanceOf( FilterExpressionNode.class ) ) );
    assertThat( filterBase.getText(), is( inputExpression ) );
    FilterExpressionNode filter = (FilterExpressionNode) filterBase;
    assertThat( filter.getExpression(), is( instanceOf( ListNode.class ) ) );
    assertThat( filter.getExpression().getText(), is( "{x:1, y:2}, {x:2, y:3}" ) );
    assertThat( filter.getFilter(), is( instanceOf( InfixOpNode.class ) ) );
    assertThat( filter.getFilter().getText(), is( "x=1" ) );
}