*/
  public CharMatcher or(CharMatcher other) {
    return new Or(this, other);
  }

  /**
   * Returns a {@code char} matcher functionally equivalent to this one, but which may be faster to
   * query than the original; your mileage may vary. Precomputation takes time and requires more
   * memory, so it is only likely to be worthwhile if the precomputed matcher is queried very often.
   *

     * implementations, supports add() under JDK8. This seems problematic, but I
     * didn't see that discussed in the review, which included many other
     * changes: https://mail.openjdk.org/pipermail/core-libs-dev/2013-May/thread.html#17367
     *
     * TODO(cpovirk): decide what the best long-term action here is: force users
     * to suppress (as we do now), stop testing entrySet().add() at all, make

  public static final String KEEP_ALIVE = "Keep-Alive";

  /**
   * The HTTP <a href="https://github.com/WICG/nav-speculation/blob/main/no-vary-search.md">{@code
   * No-Vary-Seearch}</a> header field name.
   *
   * @since 32.0.0
   */
  public static final String NO_VARY_SEARCH = "No-Vary-Search";

  /**
   * The HTTP <a href="https://googlechrome.github.io/OriginTrials/#header">{@code Origin-Trial}</a>
   * header field name.

This is very useful when you need to:

* Have shared logic (the same code logic again and again).
* Share database connections.
* Enforce security, authentication, role requirements, etc.
* And many other things...

All these, while minimizing code repetition.

## First Steps { #first-steps }

Let's see a very simple example. It will be so simple that it is not very useful, for now.

/*
 * Copyright (C) 2011 The Guava Authors
 *
 * 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

/*
 * Copyright (C) 2005 The Guava Authors
 *
 * 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,

        SmbException ex = new SmbException(123, true);
        assertEquals("123", ex.getMessage());
        assertEquals(123, ex.getNtStatus());
    }

    /**
     * Parameterised test covering many error codes.
     * - Error code 0 returns 0 (NT_STATUS_SUCCESS)
     * - Negative values with 0xC0000000 bits set are returned as-is
     * - Positive values not in DOS_ERROR_CODES map to NT_STATUS_UNSUCCESSFUL
     */

 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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,

   */
  public static <K, V> Builder<K, V> builder() {
    return new Builder<>();
  }

  /**
   * Returns a new builder with a hint for how many distinct keys are expected to be added. The
   * generated builder is equivalent to that returned by {@link #builder}, but may perform better if
   * {@code expectedKeys} is a good estimate.
   *
   * @throws IllegalArgumentException if {@code expectedKeys} is negative

     * implementations, supports add() under JDK8. This seems problematic, but I
     * didn't see that discussed in the review, which included many other
     * changes: https://mail.openjdk.org/pipermail/core-libs-dev/2013-May/thread.html#17367
     *
     * TODO(cpovirk): decide what the best long-term action here is: force users
     * to suppress (as we do now), stop testing entrySet().add() at all, make