def _get_resources(rtype='resources'):
    """ resource types from state summary include:  resources, used_resources
    offered_resources, reserved_resources, unreserved_resources
    The default is resources.

    :param rtype: the type of resources to return
    :type rtype: str
    :param role: the name of the role if for reserved and if None all reserved
    :type rtype: str

    :return: resources(cpu,mem)
    :rtype: Resources
    """
    cpus = 0
    mem = 0
    summary = DCOSClient().get_state_summary()

    if 'slaves' in summary:
        agents = summary.get('slaves')
        for agent in agents:
            if agent[rtype].get('cpus') is not None:
                cpus += agent[rtype].get('cpus')
            if agent[rtype].get('mem') is not None:
                mem += agent[rtype].get('mem')

    return Resources(cpus, mem)
resource types from state summary include:  resources, used_resources
    offered_resources, reserved_resources, unreserved_resources
    The default is resources.

    :param rtype: the type of resources to return
    :type rtype: str
    :param role: the name of the role if for reserved and if None all reserved
    :type rtype: str

    :return: resources(cpu,mem)
    :rtype: Resources