*   <li>{@link DataService} - The service for managing access results.</li>
 * </ul>
 *
 * <p>Each parameter is stored in a ThreadLocal variable to ensure thread safety.</p>
 *
 * <p>Usage example:</p>
 * <pre>
 * {@code
 * UrlQueue<?> urlQueue = CrawlingParameterUtil.getUrlQueue();
 * CrawlingParameterUtil.setUrlQueue(newUrlQueue);
 *
 * CrawlerContext context = CrawlingParameterUtil.getCrawlerContext();

        return this;
    }

    /**
     * Sets the delimiter for JavaBeans.
     * <p>
     * When copying between JavaBeans and {@link Map}, you can change the delimiter used in property names.
     * For example, if you specify an underscore as the delimiter for JavaBeans and a period as the delimiter for {@link Map},
     * the property names for the source and destination will be as follows:
     * </p>
     * <table border="1">

  /** A call that keeps track of whether its response body is closed. */
  private class ClosableCall : FailingCall() {
    private val response =
      Response
        .Builder()
        .request(Request("https://example.com/".toHttpUrl()))
        .protocol(Protocol.HTTP_1_1)
        .message("OK")
        .code(200)
        .body(
          object : ResponseBody() {
            override fun contentType() = null

 *
 * <p>To use, create a new {@link EquivalenceTester} and add equivalence groups where each group
 * contains objects that are supposed to be equal to each other. Objects of different groups are
 * expected to be unequal. For example:
 *
 * {@snippet :
 * EquivalenceTester.of(someStringEquivalence)
 *     .addEquivalenceGroup("hello", "h" + "ello")
 *     .addEquivalenceGroup("world", "wor" + "ld")
 *     .test();
 * }
 *

   * documentation for {@link Collection}:
   *
   * <blockquote>
   *
   * "Some collection implementations have restrictions on the elements that they may contain. For
   * example, some implementations prohibit null elements, and some have restrictions on the types
   * of their elements."
   *
   * </blockquote>
   */
  RESTRICTS_ELEMENTS,

  /**

     * creator of the problem, the general expectation is that the hint provides sufficient information to the user to
     * track the problem back to its origin. A concrete example for such a source hint can be the file path or URL from
     * which the settings were read.
     *
     * @return the hint about the source of the problem or an empty string if unknown, never {@code null}
     */

  }

  private fun logWithTime(message: String) {
    val startNs = startNs
    val timeMs =
      if (startNs == null) {
        // Event occurred before start, for an example an early cancel.
        0L
      } else {
        TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startNs)
      }

    logger.invoke("[$timeMs ms] $message")
  }

Just use any kind of model, any kind of class, any kind of database that you need for your application. **FastAPI** has you covered with the dependency injection system.

## Code size { #code-size }

This example might seem verbose. Keep in mind that we are mixing security, data models, utility functions and *path operations* in the same file.

But here's the key point.

The security and dependency injection stuff is written once.

 * peers. Sets of root certificates are managed by either the HTTP client (like Firefox), or the
 * host platform (like Android). In July 2018 Android had 134 trusted root certificates for its HTTP
 * clients to trust.
 *
 * For example, in order to establish a secure connection to `https://www.squareup.com/`,
 * these three certificates are used.
 *
 * ```
 * www.squareup.com certificate:
 *
 * Common Name: www.squareup.com

 * NullPointerTester}, {@link EqualsTester} and {@link SerializableTester}. For example:
 *
 * <pre>
 * public class PackageSanityTests extends AbstractPackageSanityTests {}
 * </pre>
 *
 * <p>Note that only top-level classes with either a non-private constructor or a non-private static
 * factory method to construct instances can have their instance methods checked. For example:
 *
 * <pre>
 * public class Address {