Move the element so it is on top of all other cells (element/links).
true, all the embedded cells of this
element will get higher
z index than that of this element in a Breadth-first search (BFS) fashion. This
is especially useful in hierarchical diagrams where if you want to send an element to the front, you don't want
its children (embedded cells) to be hidden behind that element.
All elements have a
z property defining their z-level in the graph. This
can even be set directly by
element.set('z', 123). This change will be automatically handled by the
object associated with the
joint.dia.Graph object this element is part of and all the SVG elements will get resorted so that
their position in the DOM reflects the