setGroupGeneric: Create a Group Generic Version of a Function
The setGroupGeneric function behaves like setGeneric
except that it constructs a group generic function, differing in two
ways from an ordinary generic function. First, this function cannot
be called directly, and the body of the function created will contain
a stop call with this information. Second, the group generic function
contains information about the known members of the group, used to
keep the members up to date when the group definition changes, through
changes in the search list or direct specification of methods, etc.
All members of the group must have the identical argument list.
the character string name of the generic function.
A function object. There isn't likely to be an existing
nongeneric of this name, so some function needs to be supplied. Any
known member or other function with the same argument list will do,
because the group generic cannot be called directly.