'Check if SLO and workload values are valid.
:param array: the array serial number
:param slo: Service Level Object e.g bronze
:param workload: workload e.g DSS
:param srp: the storage resource pool name
:returns: boolean'

def verify_slo_workload(self, array, slo, workload, srp):

    (is_valid_slo, is_valid_workload) = (False, False)
    if (workload and (workload.lower() == 'none')):
        workload = None
    if (not workload):
        is_valid_workload = True
    if (slo and (slo.lower() == 'none')):
        slo = None
    valid_slos = self.rest.get_slo_list(array)
    valid_workloads = self.rest.get_workload_settings(array)
    for valid_slo in valid_slos:
        if (slo == valid_slo):
            is_valid_slo = True
            break
    for valid_workload in valid_workloads:
        if (workload == valid_workload):
            is_valid_workload = True
            break
    if (not slo):
        is_valid_slo = True
        if workload:
            is_valid_workload = False
    if (not is_valid_slo):
        LOG.error('SLO:    %(slo)s    is    not    valid.    Valid    values    are:    %(valid_slos)s.', {'slo': slo, 'valid_slos': valid_slos})
    if (not is_valid_workload):
        LOG.error('Workload:    %(workload)s    is    not    valid.    Valid    values    are    %(valid_workloads)s.    Note    you    cannot    set    a    workload    without    an    SLO.', {'workload': workload, 'valid_workloads': valid_workloads})
    return (is_valid_slo, is_valid_workload)
