def on_slim_control(code, content)
      code = code + ' do' unless code =~ BLOCK_REGEX || empty_exp?(content)
      [:slim, :control, code, compile(content)]
    end
def on_slim_control(code, content)
      code = code + ' do' unless code =~ BLOCK_REGEX || empty_exp?(content)
      [:slim, :control, code, compile(content)]
    end
Handle control expression `[:slim, :control, code, content]`

 @param [String] code Ruby code
 @param [Array] content Temple expression
 @return [Array] Compiled temple expression