Modify a parameter group for your account.

        :type name: string
        :param name: The name of the new parameter group

        :type parameters: list of :class:`boto.rds.parametergroup.Parameter`
        :param parameters: The new parameters

        :rtype: :class:`boto.rds.parametergroup.ParameterGroup`
        :return: The newly created ParameterGroup

def modify_parameter_group(self, name, parameters=None):
        """
        Modify a parameter group for your account.

        :type name: string
        :param name: The name of the new parameter group

        :type parameters: list of :class:`boto.rds.parametergroup.Parameter`
        :param parameters: The new parameters

        :rtype: :class:`boto.rds.parametergroup.ParameterGroup`
        :return: The newly created ParameterGroup
        """
        params = {'DBParameterGroupName': name}
        for i in range(0, len(parameters)):
            parameter = parameters[i]
            parameter.merge(params, i+1)
        return self.get_list('ModifyDBParameterGroup', params,
                             ParameterGroup, verb='POST')