def inheritable_cache_get(formats, name, partial, param)
      prefixes = formats.collect { |format| inheritable_cache[format.to_sym][partial][name][param] }
      prefixes.compact!
      prefixes.empty? ?  nil : prefixes.first
    end
def inheritable_cache_get(formats, name, partial, param)
      prefixes = formats.collect { |format| inheritable_cache[format.to_sym][partial][name][param] }
      prefixes.compact!
      prefixes.empty? ?  nil : prefixes.first
    end
Gets the prefix from the cache. Returns nil if it's not there yet.