content: /*
   *
   *  * Copyright 2020 Alibaba Group Holding Limited.
   *  *
   *  * 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 com.alibaba.graphscope.common.ir.meta.glogue.calcite.handler;
  
  import com.google.common.collect.ImmutableList;
  
  import org.apache.calcite.rel.RelCollation;
  import org.apache.calcite.rel.RelNode;
  import org.apache.calcite.rel.metadata.BuiltInMetadata;
  import org.apache.calcite.rel.metadata.RelMetadataQuery;
  
  public class GraphCollationHandler implements BuiltInMetadata.Collation.Handler {
  
      @Override
      public ImmutableList<RelCollation> collations(
              RelNode relNode, RelMetadataQuery relMetadataQuery) {
          return ImmutableList.of();
      }
  }
  