* - 2 requests happen concurrently to a host that can be coalesced onto a single connection.
   * - Both request discover no existing connection. They both make a connection.
   * - The first request "wins the race".
   * - The second request discovers it "lost the race" and closes the connection it just opened.
   * - The second request uses the coalesced connection from request1.

        routes = routes,
        requireMultiplexed = planToReplace != null && planToReplace.isReady,
      ) ?: return null

    // If we coalesced our connection, remember the replaced connection's route. That way if the
    // coalesced connection later fails we don't waste a valid route.
    if (planToReplace != null) {
      nextRouteToTry = planToReplace.route
      planToReplace.closeQuietly()
    }

    coalescedRange = coalesce(coalescedRange, value, lowerEntry);

    Entry<Cut<K>, RangeMapEntry<K, V>> higherEntry =
        entriesByLowerBound.floorEntry(range.upperBound);
    coalescedRange = coalesce(coalescedRange, value, higherEntry);

    return coalescedRange;
  }

  /** Returns the range that spans the given range and entry, if the entry can be coalesced. */

    coalescedRange = coalesce(coalescedRange, value, lowerEntry);

    Entry<Cut<K>, RangeMapEntry<K, V>> higherEntry =
        entriesByLowerBound.floorEntry(range.upperBound);
    coalescedRange = coalesce(coalescedRange, value, higherEntry);

    return coalescedRange;
  }

  /** Returns the range that spans the given range and entry, if the entry can be coalesced. */

   * range set for which both {@code a.enclosesAll(b)} and {@code a.encloses(range)}.
   *
   * <p>Note that {@code range} will be {@linkplain Range#span(Range) coalesced} with any ranges in
   * the range set that are {@linkplain Range#isConnected(Range) connected} with it. Moreover, if
   * {@code range} is empty, this is a no-op.
   *

   * range set for which both {@code a.enclosesAll(b)} and {@code a.encloses(range)}.
   *
   * <p>Note that {@code range} will be {@linkplain Range#span(Range) coalesced} with any ranges in
   * the range set that are {@linkplain Range#isConnected(Range) connected} with it. Moreover, if
   * {@code range} is empty, this is a no-op.
   *

   * connection from the pool.
   *
   * Once true this is always true. Guarded by this.
   */
  var noNewExchanges = false

  /**
   * If true, this connection may not be used for coalesced requests. These are requests that could
   * share the same connection without sharing the same hostname.
   */
  private var noCoalescedConnections = false

  /**

pkg net/http/httptrace, type DNSDoneInfo struct
pkg net/http/httptrace, type DNSDoneInfo struct, Addrs []net.IPAddr
pkg net/http/httptrace, type DNSDoneInfo struct, Coalesced bool
pkg net/http/httptrace, type DNSDoneInfo struct, Err error
pkg net/http/httptrace, type DNSStartInfo struct
pkg net/http/httptrace, type DNSStartInfo struct, Host string
pkg net/http/httptrace, type GotConnInfo struct

// to the client of package reflect. In gc, the only concern is that
// a nil *rtype must be replaced by a nil Type, but in gccgo this
// function takes care of ensuring that multiple *rtype for the same
// type are coalesced into a single Type.
func toType(t *abi.Type) Type {
	if t == nil {
		return nil
	}
	return toRType(t)

   *
   * <p>This is the smallest {@code RangeSet} which encloses each of the specified ranges. Duplicate
   * or connected ranges are permitted, and will be coalesced in the result.
   *
   * @since 21.0
   */
  public static <C extends Comparable<?>> ImmutableRangeSet<C> unionOf(Iterable<Range<C>> ranges) {
    return copyOf(TreeRangeSet.create(ranges));
  }