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.operators;
  
  import io.reactivex.rxjava3.annotations.NonNull;
  import io.reactivex.rxjava3.functions.Supplier;
  
  /**
   * A marker interface indicating that a scalar, constant value
   * is held by the implementing reactive type which can be
   * safely extracted during assembly time can be used for
   * optimization.
   * <p>
   * Implementors of {@link #get()} should not throw any exception.
   * <p>
   * Design note: the interface extends {@link Supplier} because if a scalar
   * is safe to extract during assembly time, it is also safe to extract at
   * subscription time or later. This allows optimizations to deal with such
   * single-element sources uniformly.
   * <p>
   * @param <T> the scalar value type held by the implementing reactive type
   * @since 3.1.1
   */
  @FunctionalInterface
  public interface ScalarSupplier<@NonNull T> extends Supplier<T> {
  
      // overridden to remove the throws Throwable
      @Override
      T get();
  }
  