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
   * <p>
   * http://www.apache.org/licenses/LICENSE-2.0
   * <p>
   * 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.atlas.repository.graphdb;
  
  /**
   * A query against a particular vertex.
   *
   * @param <V> vertex class used by the graph
   * @param <E> edge class used by the graph
   */
  public interface AtlasVertexQuery<V, E> {
      /**
       * Specifies the edge direction that should be query.
       *
       * @param queryDirection
       * @return
       */
      AtlasVertexQuery<V, E> direction(AtlasEdgeDirection queryDirection);
  
      /**
       * Returns the vertices that satisfy the query condition.
       *
       * @return
       */
      Iterable<AtlasVertex<V, E>> vertices();
  
      /**
       * Returns the vertices that satisfy the query condition.
       *
       * @param limit Max number of vertices
       * @return
       */
      Iterable<AtlasVertex<V, E>> vertices(int limit);
  
      /**
       * Returns the incident edges that satisfy the query condition.
       * @return
       */
      Iterable<AtlasEdge<V, E>> edges();
  
      /**
       * Returns the incident edges that satisfy the query condition.
       * @param limit Max number of edges
       * @return
       */
      Iterable<AtlasEdge<V, E>> edges(int limit);
  
      /**
       * Returns the number of elements that match the query.
       * @return
       */
      long count();
  
      /**
       * Specifies the edge label that should be queried.
       *
       * @param label
       * @return
       */
      AtlasVertexQuery<V, E> label(String label);
  
      /**
       * Returns edges that matches property key and value.
       *
       * @param key
       * @param value
       * @return
       */
      AtlasVertexQuery<V, E> has(String key, Object value);
  }
  