# File lib/hiera/backend.rb, line 57
            def datasources(scope, override=nil, hierarchy=nil)
                if hierarchy
                    hierarchy = [hierarchy]
                elsif Config.include?(:hierarchy)
                    hierarchy = [Config[:hierarchy]].flatten
                else
                    hierarchy = ["common"]
                end

                hierarchy.insert(0, override) if override

                hierarchy.flatten.map do |source|
                    source = parse_string(source, scope)
                    yield(source) unless source == "" or source =~ /(^\/|\/\/|\/$)/
                end
            end