code: public java.util.List<InstanceBlockDeviceMappingSpecification> getBlockDeviceMappings() {
          if (blockDeviceMappings == null) {
              blockDeviceMappings = new com.amazonaws.internal.SdkInternalList<InstanceBlockDeviceMappingSpecification>();
          }
          return blockDeviceMappings;
      }
docs: <p>
  Modifies the <code>DeleteOnTermination</code> attribute for volumes that are currently attached. The volume must
  be owned by the caller. If no value is specified for <code>DeleteOnTermination</code>, the default is
  <code>true</code> and the volume is deleted when the instance is terminated.
  </p>
  <p>
  To add instance store volumes to an Amazon EBS-backed instance, you must add them when you launch the instance.
  For more information, see <a href=
  "https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/block-device-mapping-concepts.html#Using_OverridingAMIBDM"
  >Updating the Block Device Mapping when Launching an Instance</a> in the <i>Amazon Elastic Compute Cloud User
  Guide</i>.
  </p>
  
  @return Modifies the <code>DeleteOnTermination</code> attribute for volumes that are currently attached. The
  volume must be owned by the caller. If no value is specified for <code>DeleteOnTermination</code>, the
  default is <code>true</code> and the volume is deleted when the instance is terminated.</p>
  <p>
  To add instance store volumes to an Amazon EBS-backed instance, you must add them when you launch the
  instance. For more information, see <a href=
  "https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/block-device-mapping-concepts.html#Using_OverridingAMIBDM"
  >Updating the Block Device Mapping when Launching an Instance</a> in the <i>Amazon Elastic Compute Cloud
  User Guide</i>.