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.
   */
  
  /**
   * Provides model files, in JSON format, defining schemas and other metadata.
   *
   * <p>Models are specified using a <code>model=&lt;uri&gt;</code> parameter on
   * the JDBC connect string. Calcite loads the model while initializing the
   * connection. It first parses the JSON, then uses a
   * {@link org.apache.calcite.model.ModelHandler} as visitor over the parse
   * tree.
   *
   * <p>There are standard implementations of schema and table, but the user can
   * provide their own by implementing the
   * {@link org.apache.calcite.schema.SchemaFactory}
   * or {@link org.apache.calcite.schema.TableFactory}
   * interfaces and including a custom schema in the model.
   *
   * <p>There are several examples of schemas in the
   * <a href="https://calcite.apache.org/docs/tutorial.html">tutorial</a>.
   */
  @DefaultQualifier(value = NonNull.class, locations = TypeUseLocation.FIELD)
  @DefaultQualifier(value = NonNull.class, locations = TypeUseLocation.PARAMETER)
  @DefaultQualifier(value = NonNull.class, locations = TypeUseLocation.RETURN)
  package org.apache.calcite.model;
  
  import org.checkerframework.checker.nullness.qual.NonNull;
  import org.checkerframework.framework.qual.DefaultQualifier;
  import org.checkerframework.framework.qual.TypeUseLocation;
  