}

    protected HtmlResponse doSearch(final ListForm form) {
        validate(form, messages -> {}, this::asListHtml);

        if (StringUtil.isBlank(form.q)) {
            // query matches on all documents.
            form.q = Constants.MATCHES_ALL_QUERY;
        }
        final WebRenderData renderData = new WebRenderData();
        form.initialize();

    FIRST,
    SECOND,
    THIRD;
  }

  // Given a sequence of lock acquisition descriptions
  // (e.g. "LockA -> LockB", "LockB -> LockC", ...)
  // Checks that the exception.getMessage() matches a regex of the form:
  // "LockA -> LockB \b.*\b LockB -> LockC \b.*\b LockC -> LockA"
  private void checkMessage(IllegalStateException exception, String... expectedLockCycle) {

func fixLongPath(path string) string {
	// Do nothing (and don't allocate) if the path is "short".
	// Empirically (at least on the Windows Server 2013 builder),
	// the kernel is arbitrarily okay with < 248 bytes. That
	// matches what the docs above say:
	// "When using an API to create a directory, the specified
	// path cannot be so long that you cannot append an 8.3 file
	// name (that is, the directory name cannot exceed MAX_PATH

    String moreLines = "(?:.*" + System.lineSeparator() + "?)*";
    String expected =
        firstLine + System.lineSeparator() + secondLine + System.lineSeparator() + moreLines;
    assertThat(getStackTraceAsString(e)).matches(expected);
  }

  public void testGetCausalChain() {
    SomeUncheckedException sue = new SomeUncheckedException();
    IllegalArgumentException iae = new IllegalArgumentException(sue);

    //     we find them, regardless of what the address policies need.
    //
    //  2. EVICTABLE: Connections not required by any address policy. This matches connections that
    //     don't participate in any policy, plus connections whose policies won't be violated if the
    //     connection is closed. We only close these if the idle connection limit is exceeded.
    //

			p := IndexByte(b[i:i+15], byte(100+j))
			if p != j {
				t.Errorf("IndexByte(%q, %d) = %d", b[i:i+15], 100+j, p)
			}
		}
		for j := 0; j < 15; j++ {
			b[i+j] = 0
		}
	}
	// Make sure matches outside the slice never trigger.
	for i := 0; i <= len(b)-15; i++ {
		for j := 0; j < 15; j++ {
			b[i+j] = 1
		}
		for j := 0; j < 15; j++ {
			p := IndexByte(b[i:i+15], byte(0))
			if p != -1 {

 *
 * We define these values:
 *
 *  * **b0b1s7**: (b0 << 14) + (b1 << 7)
 *  * **b2b3s2**: (b2 << 9) + (b3 << 2)
 *
 * b0b1s7 is the section prefix. If a section is omitted, that means its ranges data exactly matches
 * that of the preceding section.
 *
 * b2b3s2 is the offset into the ranges data. It is shifted by 2 because ranges are 4-byte aligned.
 *
 * Mappings Data (4,719 bytes)
 * ===========================
 *

		}

		// Do the same for the headers.
		for key, value := range testCase.headers {
			req.Header.Set(key, value)
		}

		// parse form.
		req.ParseForm()

		// Check if it matches!
		err := doesPresignedSignatureMatch(payloadSHA256, req, testCase.region, serviceS3)
		if err != testCase.expected {
			t.Errorf("(%d) expected to get %s, instead got %s", i, niceError(testCase.expected), niceError(err))
		}

<img src="/img/tutorial/dependencies/image01.png">

## Simple usage

If you look at it, *path operation functions* are declared to be used whenever a *path* and *operation* matches, and then **FastAPI** takes care of calling the function with the correct parameters, extracting the data from the request.

Actually, all (or most) of the web frameworks work in this same way.

Similarly, you cannot redefine a path operation:

```Python hl_lines="6  11"
{!../../docs_src/path_params/tutorial003b.py!}
```

The first one will always be used since the path matches first.

## Predefined values