def METHOD_NAME(test, params, env):
    """
    Test command: virsh schedinfo.
    This version provide base test of virsh schedinfo command:
    virsh schedinfo <vm> [--set<set_ref>]
    TODO: to support more parameters.
    1) Get parameters and prepare vm's state
    2) Prepare test options.
    3) Run schedinfo command to set or get parameter.
    4) Recover environment like vm's state.
    5) Check result.
    """
    def schedinfo_output_analyse(result, set_ref, scheduler="credit"):
        """
        Get the value of set_ref.
        :param result: CmdResult struct
        :param set_ref: the parameter has been set
        :param scheduler: the scheduler of xen(default is credit)
        """
        output = result.stdout.strip()
        if not re.search("Scheduler", output):
            test.fail("Output is not standard:\n%s" % output)
        result_lines = output.splitlines()
        set_value = None
        for line in result_lines:
            key_value = line.split(":")
            key = key_value[0].strip()
            value = key_value[1].strip()
            if key == "Scheduler":
                if value != scheduler:
                    test.cancel("This test do not support"
                                " %s scheduler." % scheduler)
            elif key == set_ref:
                set_value = value
                break
        return set_value
    # Prepare vm test environment
    vm_name = params.get("main_vm")
    vm = env.get_vm(vm_name)
    domid = vm.get_id()
    domuuid = vm.get_uuid()
    # Prepare test options
    vm_ref = params.get("schedinfo_vm_ref", "domname")
    options_ref = params.get("schedinfo_options_ref", "")
    options_suffix = params.get("schedinfo_options_suffix", "")
    set_ref = params.get("schedinfo_set_ref", "")
    set_value = params.get("schedinfo_set_value", "")
    set_value_expected = params.get("schedinfo_set_value_expected", "")
    # The default scheduler on qemu/kvm is posix
    scheduler_value = "credit"
    status_error = params.get("status_error", "no")
    if vm_ref == "domid":
        vm_ref = domid
    elif vm_ref == "domname":
        vm_ref = vm_name
    elif vm_ref == "domuuid":
        vm_ref = domuuid
    elif vm_ref == "hex_id":
        if domid == '-':
            vm_ref = domid
        else:
            vm_ref = hex(int(domid))
    if set_ref == "none":
        options_ref = "--set"
        set_ref = None
    elif set_ref:
        if set_value:
            options_ref = "--set %s=%s" % (set_ref, set_value)
        else:
            options_ref = "--set %s" % set_ref
    options_ref += options_suffix
    # Run command
    result = virsh.schedinfo(vm_ref, options_ref,
                             ignore_status=True, debug=True)
    status = result.exit_status
    if vm.is_alive():
        vm.destroy()
    if set_ref:
        set_value_of_output = schedinfo_output_analyse(result, set_ref,
                                                       scheduler_value)
    # Check result
    if status_error == "no":
        if status:
            test.fail("Run failed with right command.")
        else:
            if set_ref and set_value_expected:
                logging.info("value will be set:%s\n"
                             "set value in output:%s\n"
                             "expected value:%s" % (set_value,
                                                    set_value_of_output, set_value_expected))
                if set_value_of_output is None:
                    test.fail("Get parameter %s failed." % set_ref)
                if not (set_value_expected == set_value_of_output):
                    test.fail("Run successful but value "
                              "in output is not expected.")
    else:
        if not status:
            test.fail("Run successfully with wrong command.")