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   *  to you under the Apache License, Version 2.0 (the
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  package org.apache.cayenne.access.sqlbuilder;
  
  import java.util.function.Supplier;
  
  import org.apache.cayenne.access.sqlbuilder.sqltree.Node;
  
  /**
   * @since 4.2
   */
  public abstract class BaseBuilder implements NodeBuilder {
      /**
       * Main root of this query
       */
      protected final Node root;
  
      /*
       * Following nodes are all children of root,
       * but we keep them here for quick access.
       */
      protected final Node[] nodes;
  
      public BaseBuilder(Node root, int size) {
          this.root = root;
          this.nodes = new Node[size];
      }
  
      protected Node node(int idx, Supplier<Node> nodeSupplier) {
          if(nodes[idx] == null) {
              nodes[idx] = nodeSupplier.get();
          }
          return nodes[idx];
      }
  
      @Override
      public Node build() {
          for (Node next : nodes) {
              if (next != null) {
                  root.addChild(next);
              }
          }
          return root;
      }
  
      public Node getRoot() {
          return root;
      }
  }
  