content: /*
   * Copyright (C) 2017 The Android Open Source Project
   *
   * Licensed 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 android.provider;
  
  /**
   * A builder that facilitates prohibiting its use after an instance was created with it.
   *
   * Suggested usage:
   * call {@link #checkNotUsed} in each setter, and {@link #markUsed} in {@link #build}
   *
   * @param <T> Type of object being built
   * @hide
   */
  public abstract class OneTimeUseBuilder<T> {
      private boolean used = false;
  
      protected void markUsed() {
          checkNotUsed();
          used = true;
      }
  
      protected void checkNotUsed() {
          if (used) {
              throw new IllegalStateException(
                      "This Builder should not be reused. Use a new Builder instance instead");
          }
      }
  
      /**
       * Builds the instance
       *
       * Once this method is called, this builder should no longer be used. Any subsequent calls to a
       * setter or {@code build()} will throw an exception
       */
      public abstract T build();
  }
  