# File lib/puppet/resource/type_collection.rb, line 54
54:   def add_node(instance)
55:     dupe_check(instance, @nodes) { |dupe| "Node '#{instance.name}' is already defined#{dupe.error_context}; cannot redefine" }
56: 
57:     @node_list << instance
58:     @nodes[instance.name] = instance
59:     instance
60:   end