
PASS On getting, the length attribute must return the number of nodes represented by the collection. 
PASS Changing the length adds new nodes; The number of new nodes = new length minus old length 
PASS New nodes have no value 
PASS Setting a length equal to existing length changes nothing 
PASS Setting a length lower than the old length trims nodes from the end 
PASS Setting element to null by index removed the element 
PASS Setting element by index should correctly append and replace elements 
PASS Changing the length adds new nodes; The new nodes will not copy select's prefix