public RefreshPreferences withInstanceWarmup(Integer instanceWarmup) {
        setInstanceWarmup(instanceWarmup);
        return this;
    }
<p>
A time period, in seconds, during which an instance refresh waits before moving on to replacing the next instance
after a new instance enters the <code>InService</code> state.
</p>
<p>
This property is not required for normal usage. Instead, use the <code>DefaultInstanceWarmup</code> property of
the Auto Scaling group. The <code>InstanceWarmup</code> and <code>DefaultInstanceWarmup</code> properties work
the same way. Only specify this property if you must override the <code>DefaultInstanceWarmup</code> property.
</p>
<p>
If you do not specify this property, the instance warmup by default is the value of the
<code>DefaultInstanceWarmup</code> property, if defined (which is recommended in all cases), or the
<code>HealthCheckGracePeriod</code> property otherwise.
</p>

@param instanceWarmup
       A time period, in seconds, during which an instance refresh waits before moving on to replacing the next
       instance after a new instance enters the <code>InService</code> state.</p>
       <p>
       This property is not required for normal usage. Instead, use the <code>DefaultInstanceWarmup</code>
       property of the Auto Scaling group. The <code>InstanceWarmup</code> and <code>DefaultInstanceWarmup</code>
       properties work the same way. Only specify this property if you must override the
       <code>DefaultInstanceWarmup</code> property.
       </p>
       <p>
       If you do not specify this property, the instance warmup by default is the value of the
       <code>DefaultInstanceWarmup</code> property, if defined (which is recommended in all cases), or the
       <code>HealthCheckGracePeriod</code> property otherwise.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-autoscaling/src/main/java/com/amazonaws/services/autoscaling/model/RefreshPreferences.java