The power to test if a value is an instance of the
associated exo class, or a facet instance of the
associated exo class kit. In the later case, if a facetName is provided,
then it tests only whether the argument is a facet instance of that
facet of the associated exo class kit.
The power to test if a value is an instance of the associated exo class, or a facet instance of the associated exo class kit. In the later case, if a
facetNameis provided, then it tests only whether the argument is a facet instance of that facet of the associated exo class kit.