# File lib/aws/core/xml/grammar.rb, line 205
        def list child_element_name = nil, &block
          if child_element_name
            ignore
            element(child_element_name) do |parent_element_name|
              rename(parent_element_name)
              collect_values
              yield if block_given?
            end
          else
            collect_values
          end
        end