import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import javax.annotation.CheckForNull;

/**
 * Standard implementation of {@link ValueGraph} that supports the options supplied by {@link
 * AbstractGraphBuilder}.
 *
 * <p>This class maintains a map of nodes to {@link GraphConnections}.
 *
 * <p>Collection-returning accessors return unmodifiable views: the view returned will reflect

   * Splitter.on(',').omitEmptyStrings().split(",a,,,b,c,,")} returns an iterable containing only
   * {@code ["a", "b", "c"]}.
   *
   * <p>If either {@code trimResults} option is also specified when creating a splitter, that
   * splitter always trims results first before checking for emptiness. So, for example, {@code

 *
 * <p>To decouple components, we recommend a dependency-injection framework. For Android code, most
 * apps use <a href="https://dagger.dev">Dagger</a>. For server code, common options include <a
 * href="https://github.com/google/guice/wiki/Motivation">Guice</a> and <a
 * href="https://docs.spring.io/spring-framework/docs/current/reference/html/core.html#beans-introduction">Spring</a>.

 * href="http://en.wikipedia.org/wiki/Null_Object_pattern">null object</a> for the type in question.
 *
 * <p>This class is not intended as a direct analogue of any existing "option" or "maybe" construct
 * from other programming environments, though it may bear some similarities.
 *
 * <p>An instance of this class is serializable if its reference is absent or is a serializable
 * object.
 *

       * a valid value for V.
       */
      return uncheckedNull();
    } else {
      @SuppressWarnings("unchecked") // this is the only other option
      V asV = (V) obj;
      return asV;
    }
  }

  @Override
  public boolean isDone() {
    final Object localValue = value;
    return localValue != null & !(localValue instanceof SetFuture);

       * a valid value for V.
       */
      return uncheckedNull();
    } else {
      @SuppressWarnings("unchecked") // this is the only other option
      V asV = (V) obj;
      return asV;
    }
  }

  @Override
  public boolean isDone() {
    final Object localValue = value;
    return localValue != null & !(localValue instanceof SetFuture);

  }

  public void testClosesOnErrors_copyingFromCharSourceThatThrows() {
    for (TestOption option : EnumSet.of(OPEN_THROWS, READ_THROWS, CLOSE_THROWS)) {
      TestCharSource failSource = new TestCharSource(STRING, option);
      TestCharSink okSink = new TestCharSink();
      assertThrows(IOException.class, () -> failSource.copyTo(okSink));

    this.backingThreadFactory = checkNotNull(backingThreadFactory);
    return this;
  }

  /**
   * Returns a new thread factory using the options supplied during the building process. After
   * building, it is still possible to change the options used to build the ThreadFactory and/or
   * build again. State is not shared amongst built instances.
   *
   * @return the fully constructed {@link ThreadFactory}
   */

        getMultiset().setCount(e0(), 1, 5));
    expectContents(nCopies(3, e0()));
  }

  /*
   * TODO: test that unmodifiable multisets either throw UOE or return false
   * when both are valid options. Currently we test the UOE cases and the
   * return-false cases but not their intersection
   */

    /**
     * Builds a new min-max priority queue using the previously specified options, and having no
     * initial contents.
     */
    public <T extends B> MinMaxPriorityQueue<T> create() {
      return create(Collections.<T>emptySet());
    }

    /**
     * Builds a new min-max priority queue using the previously specified options, and having the
     * given initial elements.
     */