"first-child": "jQuery.nth(a.parentNode.firstChild,1,'nextSibling')==a",
"last-child": "jQuery.nth(a.parentNode.lastChild,1,'previousSibling')==a",
"only-child": "jQuery.sibling(a.parentNode.firstChild).length==1",
"first-child": "jQuery.nth(a.parentNode.firstChild,1,'nextSibling')==a",
"last-child": "jQuery.nth(a.parentNode.lastChild,1,'previousSibling')==a",
"only-child": "jQuery.sibling(a.parentNode.firstChild).length==1",