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;
  
  import com.alibaba.graphscope.common.ir.rel.metadata.glogue.pattern.Pattern;
  import com.alibaba.graphscope.common.ir.rel.metadata.glogue.pattern.PatternEdge;
  import com.alibaba.graphscope.common.ir.rel.metadata.glogue.pattern.PatternVertex;
  
  // an interface to define the cost estimation of a pattern
  public interface CountHandler {
      double handle(Pattern pattern);
  
      default double labelConstraintsDeltaCost(PatternEdge edge, PatternVertex target) {
          return 0.0d;
      }
  }
  