def payload_params env
      # if we already specified Content-Type and which is not
      # application/x-www-form-urlencoded, then we should not
      # take payload as a part of the base_string
      if env[REQUEST_HEADERS].kind_of?(Hash)  &&
         env[REQUEST_HEADERS]['Content-Type'] &&
         env[REQUEST_HEADERS]['Content-Type'] !=
           'application/x-www-form-urlencoded'
        {}

      # if it contains any binary data,
      # then it shouldn't be application/x-www-form-urlencoded either
      # the Content-Type header would be handled in our HTTP client
      elsif contain_binary?(env[REQUEST_PAYLOAD])
        {}

      # so the Content-Type header must be application/x-www-form-urlencoded
      else
        reject_blank(env[REQUEST_PAYLOAD])
      end
    end
def payload_params env
      # if we already specified Content-Type and which is not
      # application/x-www-form-urlencoded, then we should not
      # take payload as a part of the base_string
      if env[REQUEST_HEADERS].kind_of?(Hash)  &&
         env[REQUEST_HEADERS]['Content-Type'] &&
         env[REQUEST_HEADERS]['Content-Type'] !=
           'application/x-www-form-urlencoded'
        {}

      # if it contains any binary data,
      # then it shouldn't be application/x-www-form-urlencoded either
      # the Content-Type header would be handled in our HTTP client
      elsif contain_binary?(env[REQUEST_PAYLOAD])
        {}

      # so the Content-Type header must be application/x-www-form-urlencoded
      else
        reject_blank(env[REQUEST_PAYLOAD])
      end
    end
according to OAuth 1.0a spec, only:
     Content-Type: application/x-www-form-urlencoded
 should take payload as a part of the base_string