# File lib/rspec/core/metadata.rb, line 127
        def described_class
          container_stack.each do |g|
            [:described_class, :describes].each do |key|
              if g.has_key?(key)
                value = g[key]
                return value unless value.nil?
              end
            end
          end

          container_stack.reverse.each do |g|
            candidate = g[:description_args].first
            return candidate unless String === candidate || Symbol === candidate
          end

          nil
        end