# File lib/puppet/resource/type_collection.rb, line 42
42:   def add_hostclass(instance)
43:     dupe_check(instance, @hostclasses) { |dupe| "Class '#{instance.name}' is already defined#{dupe.error_context}; cannot redefine" }
44:     dupe_check(instance, @definitions) { |dupe| "Definition '#{instance.name}' is already defined#{dupe.error_context}; cannot be redefined as a class" }
45: 
46:     @hostclasses[instance.name] = instance
47:     instance
48:   end