<documentation title="Arbitrary Parentheses Spacing">
    <standard>
    <![CDATA[
    Arbitrary sets of parentheses should have no spaces inside.
    ]]>
    </standard>
    <code_comparison>
        <code title="Valid: No spaces on the inside of a set of arbitrary parentheses.">
        <![CDATA[
$a = (null !== $extra);
        ]]>
        </code>
        <code title="Invalid: Spaces or new lines on the inside of a set of arbitrary parentheses.">
        <![CDATA[
$a = ( null !== $extra );

$a = (
    null !== $extra
);
        ]]>
        </code>
    </code_comparison>
</documentation>