</div>

This means that it will **always have a value**, it's just that sometimes the value could be `None` (or `null` in JSON).

That means that, clients using your API don't have to check if the value exists or not, they can **assume the field will always be there**, but just that in some cases it will have the default value of `None`.

    ): Headers {
      val result = Headers.Builder()

      for (index in 0 until cachedHeaders.size) {
        val fieldName = cachedHeaders.name(index)
        val value = cachedHeaders.value(index)
        if ("Warning".equals(fieldName, ignoreCase = true) && value.startsWith("1")) {
          // Drop 100-level freshness warnings.
          continue
        }
        if (isContentSpecificHeader(fieldName) ||

        .build()

    client.newCall(request).execute().use { response ->
      if (!response.isSuccessful) throw IOException("Unexpected code $response")

      for ((name, value) in response.headers) {
        println("$name: $value")
      }

      println(response.body.string())
    }
  }
}

fun main() {
  SynchronousGet().run()

        server_name  localhost;

        # To allow special characters in headers
        ignore_invalid_headers off;
        # Allow any size file to be uploaded.
        # Set to a value such as 1000m; to restrict file size to a specific value
        client_max_body_size 0;
        # To disable buffering
        proxy_buffering off;
        proxy_request_buffering off;

        location / {

        server_name  localhost;

        # To allow special characters in headers
        ignore_invalid_headers off;
        # Allow any size file to be uploaded.
        # Set to a value such as 1000m; to restrict file size to a specific value
        client_max_body_size 0;
        # To disable buffering
        proxy_buffering off;
        proxy_request_buffering off;

        location / {

          continuation.resumeWithException(e)
        }

        override fun onResponse(
          call: Call,
          response: Response,
        ) {
          continuation.resume(response) { _, value, _ ->
            value.closeQuietly()
          }
        }
      },
    )

        Map<Object, Object> mixedMap = new HashMap<>();
        mixedMap.put("key", "value");
        mixedMap.put(123, 456);
        mixedMap.put(null, "test");
        assertEquals(228L, MemoryUtil.sizeOf(mixedMap));

        // Nested maps
        Map<String, Map<String, String>> nestedMap = new HashMap<>();
        nestedMap.put("outer", Maps.map("inner", "value").$());
        assertEquals(183L, MemoryUtil.sizeOf(nestedMap));
    }

        cmdList.add("-Dfess." + getExecuteType() + ".process=true");
        if (logFilePath == null) {
            final String value = System.getProperty("fess.log.path");
            logFilePath = value != null ? value : new File(targetDir, "logs").getAbsolutePath();
        }
        cmdList.add("-Dfess.log.path=" + logFilePath);

    assertEquals(
        "getOrDefault(present, def) should return the associated value",
        v0(),
        getMap().getOrDefault(k0(), v3()));
  }

  @CollectionSize.Require(absent = ZERO)
  public void testGetOrDefault_presentNullDefault() {
    assertEquals(
        "getOrDefault(present, null) should return the associated value",
        v0(),
        getMap().getOrDefault(k0(), null));
  }

    }

    protected void assertObjectNotNull(String variableName, Object value) {
        if (variableName == null) {
            String msg = "The value should not be null: variableName=null value=" + value;
            throw new IllegalArgumentException(msg);
        }
        if (value == null) {
            String msg = "The value should not be null: variableName=" + variableName;