content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to you 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 org.apache.calcite.rel.stream;
  
  import org.apache.calcite.plan.Convention;
  import org.apache.calcite.plan.RelOptCluster;
  import org.apache.calcite.plan.RelTraitSet;
  import org.apache.calcite.rel.RelInput;
  import org.apache.calcite.rel.RelNode;
  
  import java.util.List;
  
  /**
   * Sub-class of {@link org.apache.calcite.rel.stream.Delta}
   * not targeted at any particular engine or calling convention.
   */
  public final class LogicalDelta extends Delta {
    /**
     * Creates a LogicalDelta.
     *
     * <p>Use {@link #create} unless you know what you're doing.
     *
     * @param cluster   Cluster that this relational expression belongs to
     * @param input     Input relational expression
     */
    public LogicalDelta(RelOptCluster cluster, RelTraitSet traits,
        RelNode input) {
      super(cluster, traits, input);
    }
  
    /** Creates a LogicalDelta by parsing serialized output. */
    public LogicalDelta(RelInput input) {
      super(input);
    }
  
    /** Creates a LogicalDelta. */
    public static LogicalDelta create(RelNode input) {
      final RelTraitSet traitSet = input.getTraitSet().replace(Convention.NONE);
      return new LogicalDelta(input.getCluster(), traitSet, input);
    }
  
    @Override public RelNode copy(RelTraitSet traitSet, List<RelNode> inputs) {
      return new LogicalDelta(getCluster(), traitSet, sole(inputs));
    }
  }
  