public Instance withSubnetId(String subnetId) {
        setSubnetId(subnetId);
        return this;
    }
<p>
The instance's subnet ID; applicable only if the stack is running in a VPC.
</p>

@param subnetId
       The instance's subnet ID; applicable only if the stack is running in a VPC.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-opsworks/src/main/java/com/amazonaws/services/opsworks/model/Instance.java