def core__add_param_to_url(url, param_name, param_value)
      uri = URI(url)
      params = URI.decode_www_form(uri.query || "") << [param_name, param_value]
      uri.query = URI.encode_www_form(params)
      uri.to_s
    end
def core__add_param_to_url(url, param_name, param_value)
      uri = URI(url)
      params = URI.decode_www_form(uri.query || "") << [param_name, param_value]
      uri.query = URI.encode_www_form(params)
      uri.to_s
    end
This function add a new GET param to an url string.