The IItemRendererClassFactory interface is the basic interface for beads
that generate instances of IItemRenderers. Note that this is not the same
as an mx.core.IFactory which is a lower-level interface for generating
an instance of just about anything. IItemRendererClassFactory implementations
often use IFactory to generate the actual item renderer instance, but
the IItemRendererClassFactory bead allows for more computation about which
renderer to instantiate. For example, the default implementation
in org.apache.flex.core.ItemRendererClassFactory checks for an itemRenderer
property on the strand, then looks for a default definition in CSS, but
also handles the renderer being defined in MXML in sub tags of the
ItemRendererClassFactory. Other more advanced implementations could
return different renderers based on the data item's type.