def extract_thrown_symbol exception
      return unless exception.is_a?(Exception)
      return unless s = exception.message.scan(/uncaught throw\W+(\w+)/).flatten[0]
      s.to_sym
    end
def extract_thrown_symbol exception
      return unless exception.is_a?(Exception)
      return unless s = exception.message.scan(/uncaught throw\W+(\w+)/).flatten[0]
      s.to_sym
    end
extract thrown symbol from given exception

 @param exception