/**
   * Returns the population covariance of the values. The count must be non-zero.
   *
   * <p>This is guaranteed to return zero if the dataset contains a single pair of finite values. It
   * is not guaranteed to return zero when the dataset consists of the same pair of values multiple
   * times, due to numerical errors.
   *
   * <h3>Non-finite values</h3>
   *

        List<String> keyAndValue = ImmutableList.copyOf(KEY_VALUE_SPLITTER.split(keyValuePair));
        checkArgument(!keyAndValue.isEmpty(), "blank key-value pair");
        checkArgument(
            keyAndValue.size() <= 2,
            "key-value pair %s with more than one equals sign",
            keyValuePair);

        // Find the ValueParser for the current key.
        String key = keyAndValue.get(0);

          }
        };
    EscaperAsserts.assertBasic(surrogateEscaper);

    // A surrogate pair defining a code point within the safe range.
    String safeInput = "\uD800\uDC00"; // 0x10000
    assertEquals(safeInput, surrogateEscaper.escape(safeInput));

    // A surrogate pair defining a code point outside the safe range (but both
    // of the surrogate characters lie within the safe range). It is important

    return super.asMap();
  }

  /**
   * Stores a key-value pair in the multimap.
   *
   * @param key key to store in the multimap
   * @param value value to store in the multimap
   * @return {@code true} if the method increased the size of the multimap, or {@code false} if the
   *     multimap already contained the key-value pair
   */
  @CanIgnoreReturnValue
  @Override

   *
   * <p>If {@code edge} already connects an endpoint pair equal to {@code endpoints}, then this
   * method will have no effect.
   *
   * @return {@code true} if the network was modified as a result of this call
   * @throws IllegalArgumentException if {@code edge} already exists in the graph and connects some
   *     other endpoint pair that is not equal to {@code endpoints}

 * given key agrees with the order in which the values were added.
 *
 * <p>This multimap allows duplicate key-value pairs. After adding a new key-value pair equal to an
 * existing key-value pair, the {@code ArrayListMultimap} will contain entries for both the new
 * value and the old value.
 *
 * <p>Keys and values may be null. All optional multimap methods are supported, and all returned

    /**
     * A special instance of {@link RunnableExecutorPair} that is used as a sentinel value for the
     * bottom of the stack.
     */
    private static final RunnableExecutorPair NULL_PAIR = new RunnableExecutorPair(null, null);

    static {
      try {
        UNSAFE = getUnsafe();
        HEAD_OFFSET = UNSAFE.objectFieldOffset(ExecutionListCAS.class.getDeclaredField("head"));

    assertStringHash(0xb5a4be05, "ABCDefGHI\u0799", Charsets.UTF_8);
    assertStringHash(0xfc5ba834, "毎月１日,毎週月曜日", Charsets.UTF_8);
    assertStringHash(0x8a5c3699, "surrogate pair: \uD83D\uDCB0", Charsets.UTF_8);

    assertStringHash(0, "", Charsets.UTF_16LE);
    assertStringHash(0x288418e4, "k", Charsets.UTF_16LE);
    assertStringHash(0x5a0cb7c3, "hell", Charsets.UTF_16LE);

import static com.google.common.graph.GraphConstants.ENDPOINTS_MISMATCH;
import static com.google.common.graph.GraphConstants.MULTIPLE_EDGES_CONNECTING;
import static com.google.common.graph.GraphConstants.NODE_PAIR_REMOVED_FROM_GRAPH;
import static com.google.common.graph.GraphConstants.NODE_REMOVED_FROM_GRAPH;
import static java.util.Collections.unmodifiableSet;

import com.google.common.annotations.Beta;

        if (cp < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
          return escaper.escape((char) cp);
        }
        // Convert the code point to a surrogate pair and escape them both.
        // Note: This code path is horribly slow and typically allocates 4 new
        // char[] each time it is invoked. However this avoids any