new EqualsTester()
        .addEqualityGroup(Hashing.concatenating(asList(Hashing.md5())))
        .addEqualityGroup(Hashing.concatenating(asList(Hashing.murmur3_32())))
        .addEqualityGroup(
            Hashing.concatenating(Hashing.md5(), Hashing.md5()),
            Hashing.concatenating(asList(Hashing.md5(), Hashing.md5())))
        .addEqualityGroup(
            Hashing.concatenating(Hashing.murmur3_32(), Hashing.md5()),

    new EqualsTester()
        .addEqualityGroup(Hashing.concatenating(asList(Hashing.md5())))
        .addEqualityGroup(Hashing.concatenating(asList(Hashing.murmur3_32())))
        .addEqualityGroup(
            Hashing.concatenating(Hashing.md5(), Hashing.md5()),
            Hashing.concatenating(asList(Hashing.md5(), Hashing.md5())))
        .addEqualityGroup(
            Hashing.concatenating(Hashing.murmur3_32(), Hashing.md5()),

  /**
   * Returns a hash function which computes its hash code by concatenating the hash codes of the
   * underlying hash functions together. This can be useful if you need to generate hash codes of a
   * specific length.
   *
   * <p>For example, if you need 1024-bit hash codes, you could join two {@link Hashing#sha512} hash
   * functions together: {@code Hashing.concatenating(Hashing.sha512(), Hashing.sha512())}.
   *
   * @since 19.0

  /**
   * Returns a hash function which computes its hash code by concatenating the hash codes of the
   * underlying hash functions together. This can be useful if you need to generate hash codes of a
   * specific length.
   *
   * <p>For example, if you need 1024-bit hash codes, you could join two {@link Hashing#sha512} hash
   * functions together: {@code Hashing.concatenating(Hashing.sha512(), Hashing.sha512())}.
   *
   * @since 19.0

     * format. It should not contain any other PEM-encoded blocks, but it may contain other text
     * which will be ignored.
     *
     * Encode a held certificate into this format by concatenating the results of
     * [certificatePem()][certificatePem] and [privateKeyPkcs8Pem()][privateKeyPkcs8Pem].
     *
     * [rfc_7468]: https://tools.ietf.org/html/rfc7468
     * [rfc_5208]: https://tools.ietf.org/html/rfc5208

  }

  /**
   * Evaluates whether the argument is an ISATAP address.
   *
   * <p>From RFC 5214: "ISATAP interface identifiers are constructed in Modified EUI-64 format [...]
   * by concatenating the 24-bit IANA OUI (00-00-5E), the 8-bit hexadecimal value 0xFE, and a 32-bit
   * IPv4 address in network byte order [...]"
   *
   * <p>For more on ISATAP addresses see section 6.1 of <a target="_parent"

  }

  /**
   * Evaluates whether the argument is an ISATAP address.
   *
   * <p>From RFC 5214: "ISATAP interface identifiers are constructed in Modified EUI-64 format [...]
   * by concatenating the 24-bit IANA OUI (00-00-5E), the 8-bit hexadecimal value 0xFE, and a 32-bit
   * IPv4 address in network byte order [...]"
   *
   * <p>For more on ISATAP addresses see section 6.1 of <a target="_parent"

        System.arraycopy(array, 0, newArray, 0, array.length);
        newArray[array.length] = value;
        return newArray;
    }

    /**
     * Returns an array that is the concatenation of two arrays.
     * <p>
     * If either or both arrays are {@literal null}, the other array is returned as is.
     * If either or both arrays have a length of {@literal 0}, the other array is returned as is.

    provided.
 *  Fix: Enforce that callers call `WebSocket.close()` on IO errors. Error
    handling in WebSockets is significantly improved.
 *  Fix: Don't use SPDY/3 style header concatenation for HTTP/2 request headers.
    This could have corrupted requests where multiple headers had the same name,
    as in cookies.
 *  Fix: Reject bad characters in the URL hostname. Previously characters like