assertThat(escaper.escape("\0\uFFFF")).isEqualTo("\0\uFFFF");
  }

  public void testBuilderRetainsState() {
    // Setting a safe range and unsafe replacement works as expected.
    Escapers.Builder builder = Escapers.builder();
    builder.setSafeRange('a', 'z');
    builder.setUnsafeReplacement("X");

**Key Scenarios**:
- ✅ Validates non-null streams
- ✅ Throws CrawlerSystemException for null
- ✅ Called during getText execution
- ✅ Does not consume or modify stream
- ✅ Consistent behavior across multiple calls
- ✅ Works with various InputStream types

---

### 5. TextExtractorEnhancedTest.java
**Purpose**: Test TextExtractor improvements and encoding handling.

**Key Test Areas**:
- Improved error messages with encoding

And an `APIRoute` subclass to use that custom request class.

### Create a custom `GzipRequest` class { #create-a-custom-gziprequest-class }

/// tip

This is a toy example to demonstrate how it works, if you need Gzip support, you can use the provided [`GzipMiddleware`](../advanced/middleware.md#gzipmiddleware){.internal-link target=_blank}.

///

The whole **FastAPI** framework is based to satisfy that. Autocompletion works everywhere.

You will rarely need to come back to the docs.

Here's how your editor might help you:

* in <a href="https://code.visualstudio.com/" class="external-link" target="_blank">Visual Studio Code</a>:

	if err != nil {
		t.Fatalf("reading response body failed: %v", err)
	}
	if string(body) != "hello" {
		t.Fatalf("response body incorrect: %v", string(body))
	}

	// Check that Unwrap works
	if trw.Unwrap() != rw {
		t.Fatalf("Unwrap returned wrong result: %v", trw.Unwrap())
	}
}

func TestHeadersAlreadyWritten(t *testing.T) {
	rw := httptest.NewRecorder()

///

Чтобы **изучить основы HTTPS** с точки зрения пользователя, загляните на <a href="https://howhttps.works/" class="external-link" target="_blank">https://howhttps.works/</a>.

Теперь, со стороны **разработчика**, вот несколько вещей, которые стоит держать в голове, размышляя об HTTPS:

        } catch (final CrawlerSystemException e) {
            assertEquals("The inputstream is null.", e.getMessage());
        }
    }

    /**
     * Test that validateInputStream works with various InputStream implementations.
     */
    public void test_validateInputStream_worksWithVariousStreamTypes() {
        // ByteArrayInputStream

        assertTrue(npe2.getMessage().contains("non-null"));
        verifyNoInteractions(mockDir);
    }

    /**
     * Sanity: implementing via an anonymous class works the same as a lambda.
     */
    @Test
    @DisplayName("anonymous class implementation behaves correctly")
    void anonymousClassImplementation() throws Exception {

        .tlsVersions(TlsVersion.TLS_1_3, TlsVersion.TLS_1_2)
        .supportsTlsExtensions(true)
        .build()

    /**
     * A modern TLS configuration that works on most client platforms and can connect to most servers.
     * This is OkHttp's default configuration.
     */
    @JvmField
    val MODERN_TLS =
      Builder(true)

## First Steps { #first-steps }

Let's see a very simple example. It will be so simple that it is not very useful, for now.

But this way we can focus on how the **Dependency Injection** system works.

### Create a dependency, or "dependable" { #create-a-dependency-or-dependable }

Let's first focus on the dependency.