* **`400 - 499`** are for "Client error" responses. These are the second type you would probably use the most.
    * An example is `404`, for a "Not Found" response.
    * For generic errors from the client, you can just use `400`.

import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.ListFeature;
import java.lang.reflect.Method;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code set()} operations on a list. Can't be invoked directly;
 * please see {@link com.google.common.collect.testing.ListTestSuiteBuilder}.
 *
 * @author George van den Driessche
 */
@GwtCompatible

import com.google.common.collect.testing.testers.TestExceptions.SomeUncheckedException;
import java.util.Map;
import junit.framework.AssertionFailedError;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@link Map#computeIfAbsent}. Can't be invoked directly; please
 * see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.MapFeature;
import java.util.Map;
import java.util.Map.Entry;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@link Map#putIfAbsent}. Can't be invoked directly; please see
 * {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

import com.google.common.collect.testing.features.MapFeature;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.Map.Entry;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code remove} operations on a map. Can't be invoked directly;
 * please see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author George van den Driessche
 * @author Chris Povirk

import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.MapFeature;
import java.util.Map;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@link Map#replace(Object, Object, Object)}. Can't be invoked
 * directly; please see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

func ErrorToErr(err error) Err {
	if err == nil {
		return Err{}
	}

	// If this is already a Err, do nothing
	if e, ok := err.(Err); ok {
		return e
	}

	// Show a generic message for known golang errors
	if errors.Is(err, syscall.EADDRINUSE) {
		return ErrPortAlreadyInUse(err).Msg("Specified port is already in use")
	} else if errors.Is(err, syscall.EACCES) || errors.Is(err, syscall.EPERM) {

import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.MapFeature;
import java.util.Map;
import java.util.Map.Entry;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@link Map#putIfAbsent}. Can't be invoked directly; please see
 * {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

import com.google.common.collect.testing.testers.TestExceptions.SomeUncheckedException;
import java.util.Map;
import java.util.Map.Entry;
import junit.framework.AssertionFailedError;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@link Map#computeIfPresent}. Can't be invoked directly; please
 * see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

import com.google.common.collect.testing.features.MapFeature;
import java.lang.reflect.Method;
import java.util.List;
import java.util.Map.Entry;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests creation (typically through a constructor or static factory
 * method) of a map. Can't be invoked directly; please see {@link
 * com.google.common.collect.testing.MapTestSuiteBuilder}.
 *