Models a simple selector.
CSS Selectors are composed of one or more simple selectors, where each simple selector may have any of the following components:
For performance reasons, this object has been kept as sparse as possible.
adjacent
directDescendant
anotherSelector
sibling
anyDescendant
$element :
$ns :
$id :
$classes :
$attributes :
$pseudoClasses :
$pseudoElements :
$combinator :
attributeOperator( $code)
combinatorOperator( $code)
__construct()
notEmpty()
__tostring()