*
 * <ul>
 *   <li>NullAway, which <a
 *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treats it
 *       identically to {@code Nullable}</a> as of version 0.9.9.
 *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>, maybe: It might no longer be
 *       necessary there, since we have stopped using the {@code @ParametersAreNonnullByDefault}

 *
 * <ul>
 *   <li>NullAway, which <a
 *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treats it
 *       identically to {@code Nullable}</a> as of version 0.9.9.
 *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>, maybe: It might no longer be
 *       necessary there, since we have stopped using the {@code @ParametersAreNonnullByDefault}

    connections.count {
      it.withLock { it.calls.isEmpty() }
    }

  fun connectionCount(): Int = connections.size

  /**
   * Attempts to acquire a recycled connection to [address] for [connectionUser]. Returns the connection if it
   * was acquired, or null if no connection was acquired. The acquired connection will also be
   * given to [connectionUser] who may (for example) assign it to a [RealCall.connection].
   *

/*
 * © 2025 CodeLibs, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of

        list.add("ccc");

        final IndexedIterator<String> it = new IndexedIterator<String>(list.iterator());

        assertThat(it.hasNext(), is(true));

        final Indexed<String> indexed1 = it.next();
        assertThat(indexed1.getIndex(), is(0));
        assertThat(indexed1.getElement(), is("aaa"));

        final Indexed<String> indexed2 = it.next();
        assertThat(indexed2.getIndex(), is(1));

 *
 * <ul>
 *   <li>NullAway, which <a
 *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treats it
 *       identically to {@code Nullable}</a> as of version 0.9.9.
 *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>, maybe: It might no longer be
 *       necessary there, since we have stopped using the {@code @ParametersAreNonnullByDefault}

 *
 * <ul>
 *   <li>NullAway, which <a
 *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treats it
 *       identically to {@code Nullable}</a> as of version 0.9.9.
 *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>, maybe: It might no longer be
 *       necessary there, since we have stopped using the {@code @ParametersAreNonnullByDefault}

 *
 * <ul>
 *   <li>NullAway, which <a
 *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treats it
 *       identically to {@code Nullable}</a> as of version 0.9.9.
 *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>, maybe: It might no longer be
 *       necessary there, since we have stopped using the {@code @ParametersAreNonnullByDefault}

 *
 * <ul>
 *   <li>NullAway, which <a
 *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treats it
 *       identically to {@code Nullable}</a> as of version 0.9.9.
 *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>, maybe: It might no longer be
 *       necessary there, since we have stopped using the {@code @ParametersAreNonnullByDefault}

 *
 * <ul>
 *   <li>NullAway, which <a
 *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treats it
 *       identically to {@code Nullable}</a> as of version 0.9.9.
 *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>, maybe: It might no longer be
 *       necessary there, since we have stopped using the {@code @ParametersAreNonnullByDefault}