exist?

# File activesupport/lib/active_support/cache.rb, line 381
      def exist?(name, options = nil)
        options = merged_options(options)
        instrument(:exist?, name) do |payload|
          entry = read_entry(namespaced_key(name, options), options)
          if entry && !entry.expired?
            true
          else
            false
          end
        end
      end