code: /*
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * 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 io.reactivex.rxjava3.exceptions;
  
  /**
   * Indicates that an operator attempted to emit a value but the downstream wasn't ready for it.
   */
  public final class MissingBackpressureException extends RuntimeException {
  
      private static final long serialVersionUID = 8517344746016032542L;
  
      /**
       * The default error message.
       * <p>
       * This can happen if the downstream doesn't call {@link org.reactivestreams.Subscription#request(long)}
       * in time or at all.
       * @since 3.1.6
       */
      public static final String DEFAULT_MESSAGE = "Could not emit value due to lack of requests";
  
      /**
       * Constructs a MissingBackpressureException without message or cause.
       */
      public MissingBackpressureException() {
          // no message
      }
  
      /**
       * Constructs a MissingBackpressureException with the given message but no cause.
       * @param message the error message
       */
      public MissingBackpressureException(String message) {
          super(message);
      }
  
      /**
       * Constructs a new {@code MissingBackpressureException} with the
       * default message {@value #DEFAULT_MESSAGE}.
       * @return the new {@code MissingBackpressureException} instance.
       * @since 3.1.6
       */
      public static MissingBackpressureException createDefault() {
          return new MissingBackpressureException(DEFAULT_MESSAGE);
      }
  }
  