If a client tries to send some **extra headers**, they will receive an **error** response.

For example, if the client tries to send a `tool` header with a value of `plumbus`, they will receive an **error** response telling them that the header parameter `tool` is not allowed:

```json
{
    "detail": [
        {
            "type": "extra_forbidden",
            "loc": ["header", "tool"],

    // Using a try/catch seems lazy, but the catch block will rarely get invoked (except for
    // durations longer than approximately +/- 292 years).
    try {
      return duration.toNanos();
    } catch (ArithmeticException tooBig) {
      return duration.isNegative() ? Long.MIN_VALUE : Long.MAX_VALUE;
    }
  }

  private Internal() {}

import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.atomic.AtomicLong;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * RDMA buffer manager for efficient memory region pooling.
 *
 * Manages pools of pre-registered memory regions to avoid the overhead
 * of frequent registration/deregistration during RDMA operations.
 */
public class RdmaBufferManager implements AutoCloseable {

Since HTTP requests frequently happen in parallel, connection pooling must be thread-safe.

These are the primary classes involved with establishing, sharing, and terminating connections:

 *  Fix: Improve `CONNECT` handling for misbehaving HTTP proxies.
 *  Fix: Don't retry requests that failed due to timeouts.
 *  Fix: Cache 302s and 308s that include appropriate response headers.
 *  Fix: Improve pooling of connections that use proxy selectors.
 *  Fix: Don't leak connections when using ALPN on the desktop.
 *  Fix: Update Jetty ALPN to `7.1.2.v20141202` (Java 7) and `8.1.2.v20141202` (Java 8).

For example, when you type `python` in the terminal, the operating system looks for a program called `python` in the **first directory** in that list.

If it finds it, then it will **use it**. Otherwise it keeps looking in the **other directories**.

### Installing Python and Updating the `PATH` { #installing-python-and-updating-the-path }

When you install Python, you might be asked if you want to update the `PATH` environment variable.

    void testNullIsNotInstance() {
        // Assert
        assertFalse(SessionSetupHandler.class.isInstance(null));
    }

    @Test
    @DisplayName("Invalid: looking up constructor on interface fails")
    void testNoConstructorLookup() {
        // Act & Assert: interfaces have no constructors

        // even if you set true manually and forget to set false back
        direction.directFrameworkDebug(fessConfig.isFrameworkDebug()); // basically false

        // you can add your own process when your application is booting or closing
        direction.directCurtainBefore(createCurtainBeforeHook());
        direction.directCurtainFinally(createCurtainFinallyHook()); // when destroy

        direction.directSecurity(createSecurityResourceProvider());

        Map<String, Integer> validPluginCounts = new HashMap<>();

        String testPluginArtifactId = "maven-compiler-plugin";

        // this is the plugin we're looking for.
        validPluginCounts.put(testPluginArtifactId, 0);

        // these are injected if -DperformRelease=true
        validPluginCounts.put("maven-deploy-plugin", 0);

        assertEquals(scopeValue, artifact.getScope(), "Check scope");
    }

    private Artifact getArtifact(MavenProject project, String groupId, String artifactId) {
        System.out.println("[ Looking for " + groupId + ":" + artifactId + " ]");
        for (Artifact a : project.getArtifacts()) {
            System.out.println(a.toString());