when the target list is being assembled, the items for this rule go first. If
more than one rule defines a first item (for a given instance of mapping)
then this is an error.
when the target list is being assembled, the items for this rule go last. If
more than one rule defines a last item (for a given instance of mapping) then
this is an error.
Returns the enum constant of this type with the specified name.
The string must match exactly an identifier used to declare an
enum constant in this type. (Extraneous whitespace characters are
not permitted.)
Parameters:
name - the name of the enum constant to be returned.