content: /*
   * Copyright (C) 2020 ActiveJ LLC.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package io.activej.dataflow.node.impl;
  
  import io.activej.common.annotation.ExposedInternals;
  import io.activej.dataflow.graph.StreamId;
  import io.activej.dataflow.graph.Task;
  import io.activej.dataflow.node.AbstractNode;
  import io.activej.datastream.supplier.StreamSuppliers;
  
  import java.util.Collection;
  import java.util.List;
  
  /**
   * Represents a node, which produces no items.
   */
  @ExposedInternals
  public final class EmptySupplier extends AbstractNode {
  	public final StreamId output;
  
  	public EmptySupplier(int index, StreamId output) {
  		super(index);
  		this.output = output;
  	}
  
  	@Override
  	public Collection<StreamId> getOutputs() {
  		return List.of(output);
  	}
  
  	@Override
  	public void createAndBind(Task task) {
  		task.export(output, StreamSuppliers.empty());
  	}
  
  	@Override
  	public String toString() {
  		return "SupplierEmpty{output=" + output + '}';
  	}
  }
  