### Exception Hierarchy

```
CrawlerSystemException (unchecked)  # Setup/config errors
CrawlingAccessException (checked)   # Runtime crawl errors
  ├─ MaxLengthExceededException
  └─ ChildUrlsException
ExtractException (checked)          # Extraction failures
  └─ UnsupportedExtractException
```

### Thread-Local Storage

```java
// Set (in CrawlerThread)

@FunctionalInterface
public interface MavenPluginPrerequisitesChecker extends Consumer<PluginDescriptor> {
    /**
     *
     * @param pluginDescriptor the plugin descriptor to check
     * @throws IllegalStateException in case the checked prerequisites are not met
     */
    @Override
    void accept(PluginDescriptor pluginDescriptor);

{* ../../docs_src/body_nested_models/tutorial005_py310.py hl[2,8] *}

The string will be checked to be a valid URL, and documented in JSON Schema / OpenAPI as such.

## Attributes with lists of submodels { #attributes-with-lists-of-submodels }

You can also use Pydantic models as subtypes of `list`, `set`, etc.:

		if output[0] == "" {
			// spurious blank caused by Split on "\n"
			output = output[1:]
			continue
		}
		t.Errorf("unexpected output: %q", output[0])
		output = output[1:]
	}

	// Checked printing.
	// Now check machine code layout.

	top := pList.Firstpc
	var text *obj.LSym
	ok = true
	ctxt.DiagFunc = func(format string, args ...any) {
		t.Errorf(format, args...)
		ok = false
	}

These custom validators are for things that can be checked with **only** the **same data** provided in the request.

///

### Understand that Code { #understand-that-code }

     * indicating that the URL should not be crawled. Otherwise, it returns {@code true}.
     *
     * @param paramMap the parameter map containing potential exclusion patterns
     * @param url the URL to be checked for crawlability
     * @return {@code true} if the URL is crawlable; {@code false} if it matches the exclusion pattern
     */
    protected boolean isUrlCrawlable(final DataStoreParams paramMap, final String url) {

    errors += path_errors + query_errors + header_errors + cookie_errors
    if dependant.body_params:
        (
            body_values,
            body_errors,
        ) = await request_body_to_args(  # body_params checked above
            body_fields=dependant.body_params,
            received_body=body,
            embed_body_fields=embed_body_fields,
        )
        values.update(body_values)
        errors.extend(body_errors)

    @Override
    public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {}
  }

  /**
   * A CyclicBarrier that uses timed await and fails with AssertionFailedErrors instead of throwing
   * checked exceptions.
   */
  public class CheckedBarrier extends CyclicBarrier {
    public CheckedBarrier(int parties) {
      super(parties);
    }

    @Override
    public int await() {

		file     string    // Test input file
		obscured bool      // Obscured with obscuretestdata package
		headers  []*Header // Expected output headers
		chksums  []string  // CRC32 checksum of files, leave as nil if not checked
		err      error     // Expected error to occur
	}{{
		file: "testdata/gnu.tar",
		headers: []*Header{{
			Name:     "small.txt",
			Mode:     0640,
			Uid:      73025,
			Gid:      5000,
			Size:     5,

- Kube-proxy: Checked whether IPv6 was available on Linux before using it. ([#131265](https://github.com/kubernetes/kubernetes/pull/131265), [@rikatz](https://github.com/rikatz))