lib/oxidized/manager.rb
def loader(hash, global_dir, local_dir, name)
      dir   = File.join(Config::Root, local_dir)
      map   = Manager.load(dir, name) if File.exist? File.join(dir, name + ".rb")
      map ||= Manager.load(global_dir, name)
      hash.merge!(map) if map
    end
def loader(hash, global_dir, local_dir, name)
      dir   = File.join(Config::Root, local_dir)
      map   = Manager.load(dir, name) if File.exist? File.join(dir, name + ".rb")
      map ||= Manager.load(global_dir, name)
      hash.merge!(map) if map
    end
if local version of file exists, load it, else load global - return falsy value if nothing loaded