def has json_path, json=nil
      if json.nil?
        json = JSON.parse body
      end
      not JsonPath.new(json_path).on(json).empty?
    end
def has json_path, json=nil
      if json.nil?
        json = JSON.parse body
      end
      not JsonPath.new(json_path).on(json).empty?
    end
Check if given JSON path exists
 @param json_path [String] a valid JSON path expression
 @param json [String] optional JSON from which to check JSON path, default to response body
 @return [true, false] true if JSON path is valid and exists, false otherwise