public Boolean isSingleInstanceType() {
        return this.singleInstanceType;
    }
<p>
Indicates that the fleet uses a single instance type to launch all Spot Instances in the fleet.
</p>
<p>
Supported only for fleets of type <code>instant</code>.
</p>

@return Indicates that the fleet uses a single instance type to launch all Spot Instances in the fleet.</p>
        <p>
        Supported only for fleets of type <code>instant</code>.
aws-java-sdk-ec2/src/main/java/com/amazonaws/services/ec2/model/SpotOptionsRequest.java