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
   *
   *        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 org.apache.causeway.core.metamodel.spec.feature;
  
  import org.apache.causeway.commons.internal.exceptions._Exceptions;
  import org.apache.causeway.commons.internal.reflection._GenericResolver.ResolvedType;
  import org.apache.causeway.commons.semantics.CollectionSemantics;
  
  /**
   * Base interface for {@link OneToManyAssociation} only.
   *
   * <p>
   * Introduced for symmetry with {@link OneToOneFeature}; if we ever support
   * collections as parameters then would also be the base interface for a
   * <tt>OneToManyActionParameter</tt>.
   *
   * <p>
   * Is also the route up to the {@link ObjectFeature} superinterface.
   *
   */
  public interface OneToManyFeature extends ObjectFeature {
  
      ResolvedType getTypeOfAnyCardinality();
  
      default CollectionSemantics getCollectionSemantics() {
          return getTypeOfAnyCardinality().collectionSemantics()
                  .orElseThrow(()->_Exceptions.unrecoverable(
                          "framework bug: non-scalar %s feature must have a TypeOfFacet",
                          this.getFeatureIdentifier()));
      }
  
  }
  