code: /*
   * Copyright (c) 2019 the Eclipse Milo Authors
   *
   * This program and the accompanying materials are made
   * available under the terms of the Eclipse Public License 2.0
   * which is available at https://www.eclipse.org/legal/epl-2.0/
   *
   * SPDX-License-Identifier: EPL-2.0
   */
  
  package org.eclipse.milo.opcua.stack.core;
  
  import java.util.Optional;
  
  import org.eclipse.milo.opcua.stack.core.types.builtin.NodeId;
  import org.eclipse.milo.opcua.stack.core.types.builtin.QualifiedName;
  
  public interface ReferenceType {
  
      /**
       * @return the {@link NodeId} that identifies this {@link ReferenceType}.
       */
      NodeId getNodeId();
  
      /**
       * @return the {@link QualifiedName} that identifies this {@link ReferenceType}.
       */
      QualifiedName getBrowseName();
  
      /**
       * @return the inverse name of the reference, i.e. the meaning of the reference as seen from the target node.
       */
      Optional<String> getInverseName();
  
      /**
       * @return {@code true} if the reference is the same as seen from the source node and the target node.
       */
      boolean isSymmetric();
  
      /**
       * @return {@code true} if the reference is an abstract reference type, i.e. no references of this type exist, only
       * references of its subtypes.
       */
      boolean isAbstract();
  
      /**
       * @return the {@link NodeId} of the super type of this reference type.
       * All references except the root reference type have a super type.
       */
      Optional<NodeId> getSuperTypeId();
  
  }
  