* This is like [toLowerCase] except that it does nothing if this contains any non-ASCII
   * characters. We want to avoid lower casing special chars like U+212A (Kelvin symbol) because
   * they can return ASCII characters that match real hostnames.
   */
  private fun String.asciiToLowercase(): String {
    return when {
      isAscii() -> lowercase(Locale.US) // This is an ASCII string.
      else -> this
    }
  }

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.net;

import com.google.common.base.Ascii;
import com.google.common.base.Joiner;
import com.google.common.base.Splitter;
import com.google.common.collect.ImmutableBiMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Lists;

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.google.common.reflect;

import static com.google.common.base.Charsets.US_ASCII;
import static com.google.common.base.StandardSystemProperty.JAVA_CLASS_PATH;
import static com.google.common.base.StandardSystemProperty.OS_NAME;
import static com.google.common.base.StandardSystemProperty.PATH_SEPARATOR;

            status_code=HTTP_401_UNAUTHORIZED,
            detail="Invalid authentication credentials",
            headers=unauthorized_headers,
        )
        try:
            data = b64decode(param).decode("ascii")
        except (ValueError, UnicodeDecodeError, binascii.Error):
            raise invalid_user_credentials_exc  # noqa: B904
        username, separator, password = data.partition(":")
        if not separator:

    if not is_windows() or sys.version_info[0] != 2:
      return env
    for k, v in env.items():
      if isinstance(k, unicode):
        k = k.encode('ascii')
      if isinstance(v, unicode):
        v = v.encode('ascii')
      env[k] = v
    return env

  cuda_libraries = ['cuda', 'cudnn']
  if is_linux():
    if int(environ_cp.get('TF_NEED_TENSORRT', False)):

 *  Fix: Fail fast when the cache is corrupted.
 *  Fix: Fail fast when a private key cannot be encoded.
 *  Fix: Fail fast when attempting to verify a non-ASCII hostname.
 *  Upgrade: [GraalVM 21][graalvm_21].
 *  Upgrade: [Kotlin 1.4.20][kotlin_1_4_20].


## Version 5.0.0-alpha.1

_2021-01-30_

**This release adds initial support for [GraalVM][graalvm].**

    encapsulation enabled.
 *  Fix: Strictly verify hostnames used with OkHttp's `HostnameVerifier`. Programs that make direct
    manual calls to `HostnameVerifier` could be defeated if the hostnames they pass in are not
    strictly ASCII. This issue is tracked as [CVE-2021-0341].


## Version 4.9.1

_2021-01-30_

 *  Fix: Work around a crash in Android 10 and 11 that may be triggered when two threads

    executeSynchronously(Request(server.url("/")))
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(0)
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(1)
  }

  /** We forbid non-ASCII characters in outgoing request headers, but accept UTF-8.  */
  @Test
  fun responseHeaderParsingIsLenient() {
    val headersBuilder = Headers.Builder()
    headersBuilder.add("Content-Length", "0")

Khanna, Karel Ha, karllessard, Koan-Sin Tan, Konstantin Beluchenko, Kulin Seth, Kun Lu, Kyle Gerard Felker, Leopold Cambier, Lianmin Zheng, linlifan, liuyuanqiang, Lukas Geiger, Luke Hutton, Mahmoud Abuzaina, Manas Mohanty, Mateo Fidabel, Maxiwell S. Garcia, Mayank Raunak, mdfaijul, meatybobby, Meenakshi Venkataraman, Michael Holman, Nathan John Sircombe, Nathan Luehr, nitins17, Om Thakkar, Patrice Vignola, Pavani Majety, per1234, Philipp Hack, pollfly, Prianka Liz Kariat, Rahul Batra, rahulbatra85,...

- Added a alpha feature, behind the `RelaxedEnvironmentVariableValidation` feature gate.
  When that gate is enabled, Kubernetes allows almost all printable ASCII characters to be used in the names
  of environment variables for containers in Pods. ([#123385](https://github.com/kubernetes/kubernetes/pull/123385), [@HirazawaUi](https://github.com/HirazawaUi))