class DataStreamerFuture extends GridFutureAdapter<Object> {
    /** Data loader. */
    @GridToStringExclude
    private DataStreamerImpl dataLdr;

    /**
     * @param dataLdr Data streamer.
     */
    DataStreamerFuture(DataStreamerImpl dataLdr) {
        assert dataLdr != null;

        this.dataLdr = dataLdr;
    }

    /** {@inheritDoc} */
    @Override public boolean cancel() throws IgniteCheckedException {<FILL_FUNCTION_BODY>}

    /** {@inheritDoc} */
    @Override public String toString() {
        return S.toString(DataStreamerFuture.class, this, super.toString());
    }
}

        if (onCancelled()) {
            dataLdr.closeEx(true);

            return true;
        }

        return false;
    
<methods>public non-sealed void <init>() ,public boolean cancel() throws org.apache.ignite.IgniteCheckedException,public IgniteInternalFuture<T> chain(IgniteClosure<? super IgniteInternalFuture<java.lang.Object>,T>) ,public IgniteInternalFuture<T> chain(IgniteOutClosure<T>) ,public IgniteInternalFuture<T> chain(IgniteClosure<? super IgniteInternalFuture<java.lang.Object>,T>, java.util.concurrent.Executor) ,public IgniteInternalFuture<T> chain(IgniteOutClosure<T>, java.util.concurrent.Executor) ,public IgniteInternalFuture<T> chainCompose(IgniteClosure<? super IgniteInternalFuture<java.lang.Object>,IgniteInternalFuture<T>>) ,public IgniteInternalFuture<T> chainCompose(IgniteClosure<? super IgniteInternalFuture<java.lang.Object>,IgniteInternalFuture<T>>, java.util.concurrent.Executor) ,public java.lang.Throwable error() ,public java.lang.Object get() throws org.apache.ignite.IgniteCheckedException,public java.lang.Object get(long) throws org.apache.ignite.IgniteCheckedException,public java.lang.Object get(long, java.util.concurrent.TimeUnit) throws org.apache.ignite.IgniteCheckedException,public java.lang.Object getUninterruptibly() throws org.apache.ignite.IgniteCheckedException,public void ignoreInterrupts() ,public boolean isCancelled() ,public boolean isDone() ,public boolean isFailed() ,public void listen(IgniteInClosure<? super IgniteInternalFuture<java.lang.Object>>) ,public void listen(org.apache.ignite.lang.IgniteRunnable) ,public org.apache.ignite.IgniteLogger logger() ,public boolean onCancelled() ,public final boolean onDone() ,public final boolean onDone(java.lang.Object) ,public final boolean onDone(java.lang.Throwable) ,public boolean onDone(java.lang.Object, java.lang.Throwable) ,public void reset() ,public java.lang.Object result() ,public java.lang.String toString() <variables>private static final java.lang.Object CANCELLED,private static final java.lang.String DONE,private static final org.apache.ignite.internal.util.future.GridFutureAdapter.Node INIT,private volatile boolean ignoreInterrupts,private volatile java.lang.Object state,private static final AtomicReferenceFieldUpdater<GridFutureAdapter#RAW,java.lang.Object> stateUpdater