AutoScalingGroup: add alarm in Policy

How do I add one alarm in a policy?

My code
```
def scalingpolicy_group(name):
return ScalingPolicy(
'testescalingpolicy',
AutoScalingGroupName=Ref(autoscaling_group(name)),
PolicyType="SimpleScaling",
AdjustmentType="PercentChangeInCapacity",
Cooldown='300',
ScalingAdjustment=1,

)

def alarm_scalingpolicy(name):
return Alarm(
'cloudwatch',
AlarmName='CW_Alarme',
Statistic='Average',
ComparisonOperator='GreaterThanOrEqualToThreshold',
EvaluationPeriods=5,
Unit='Percent',
MetricName='CPUUtilization',
Namespace='AWS/EC2',
Threshold='70.0',
Period=60,
Dimensions=[MetricDimension(
Name='AutoScalingGroupName',
Value=Ref(autoscaling_group(name))
)]
)
```