public java.util.List<BlockDeviceMapping> getBlockDeviceMappings() {
        if (blockDeviceMappings == null) {
            blockDeviceMappings = new com.amazonaws.internal.SdkInternalList<BlockDeviceMapping>();
        }
        return blockDeviceMappings;
    }
<p>
The block device mapping, which defines the EBS volumes and instance store volumes to attach to the instance at
launch. For more information, see <a
href="https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/block-device-mapping-concepts.html">Block device
mappings</a> in the <i>Amazon EC2 User Guide</i>.
</p>

@return The block device mapping, which defines the EBS volumes and instance store volumes to attach to the
        instance at launch. For more information, see <a
        href="https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/block-device-mapping-concepts.html">Block
        device mappings</a> in the <i>Amazon EC2 User Guide</i>.
aws-java-sdk-ec2/src/main/java/com/amazonaws/services/ec2/model/RunInstancesRequest.java