Let's first see how the normal API app would look like before adding the callback.

It will have a *path operation* that will receive an `Invoice` body, and a query parameter `callback_url` that will contain the URL for the callback.

This part is pretty normal, most of the code is probably already familiar to you:

{* ../../docs_src/openapi_callbacks/tutorial001_py310.py hl[7:11,34:51] *}

/// tip

    public String toString() {
      return "Files.asByteSource(" + file + ")";
    }
  }

  /**
   * Returns a new {@link ByteSink} for writing bytes to the given file. The given {@code modes}
   * control how the file is opened for writing. When no mode is provided, the file will be
   * truncated before writing. When the {@link FileWriteMode#APPEND APPEND} mode is provided, writes

                "Message should contain problem count and error count");

        assertTrue(message.contains("[com.example:project1:1.0]"), "Message should contain project1 identifier");

        assertTrue(message.contains("[com.example:project2:1.0]"), "Message should contain project2 identifier");

        assertTrue(

  }

  companion object {
    /**
     * Cache control request directives that require network validation of responses. Note that such
     * requests may be assisted by the cache via conditional GET requests.
     */
    @JvmField
    val FORCE_NETWORK = commonForceNetwork()

    /**
     * Cache control request directives that uses the cache only, even if the cached response is

        assertEquals(2, downstreamProjects.size());
        assertTrue(downstreamProjects.contains(dProject), "Expected " + downstreamProjects + " to contain " + dProject);
        assertTrue(downstreamProjects.contains(eProject), "Expected " + downstreamProjects + " to contain " + eProject);
    }

    @Test
    void testGetSortedProjects() throws DuplicateProjectException, CycleDetectedException {

     * and that the expecption message contains the expected and actual <abbr>GAV</abbr>.
     *
     * @param expectedGAV the actual <abbr>GAV</abbr> that the exception message should contain
     * @param actualGAV the actual <abbr>GAV</abbr> that the exception message should contain
     */
    private void assertExceptionMessageContains(String expectedGAV, String actualGAV) {
        String cause = assertThrows(

      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the
      direction or management of such entity, whether by contract or

  }

  protected void expectMissingKeys(K... elements) {
    for (K element : elements) {
      assertFalse("Should not contain key " + element, getMap().containsKey(element));
    }
  }

  protected void expectMissingValues(V... elements) {
    for (V element : elements) {
      assertFalse("Should not contain value " + element, getMap().containsValue(element));
    }
  }

  /**

    bytesIn.writeByte(0x58) // == Literal indexed ==
    // Indexed name (idx = 24) -> cache-control
    bytesIn.writeByte(0x08) // Literal value (len = 8)
    bytesIn.writeUtf8("no-cache")
  }

  private fun checkReadSecondRequestWithoutHuffman() {
    assertThat(hpackReader!!.headerCount).isEqualTo(2)

    // [  1] (s =  53) cache-control: no-cache
    var entry = hpackReader!!.dynamicTable[readerHeaderTableLength() - 2]!!

			// validation needed.
			continue
		case !strings.Contains(output, line1):
			t.Errorf("Testcase %d: output '%s' did not contain line 1: '%s'", i+1, output, line1)
		case !strings.Contains(output, line2):
			t.Errorf("Testcase %d: output '%s' did not contain line 2: '%s'", i+1, output, line2)
		}
	}