assertThrows(NullPointerException.class, () -> getMap().putIfAbsent(null, v3()));
    expectUnchanged();
    expectNullKeyMissingWhenNullKeysUnsupported(
        "Should not contain null key after unsupported putIfAbsent(null, value)");
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)
  public void testPutIfAbsent_nullValueUnsupported() {

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

        assertEquals(2, authorizations.size(), "The authorizations list should contain two elements.");
        assertTrue(authorizations.contains(mockAuthData1), "The list should contain the first mocked auth data.");
        assertTrue(authorizations.contains(mockAuthData2), "The list should contain the second mocked auth data.");
    }

        for (final String cmd : processedCommands) {
            assertFalse("Command should not contain ${url}", cmd.contains("${url}"));
            assertFalse("Command should not contain ${outputFile}", cmd.contains("${outputFile}"));
            assertTrue("Command should contain temp path", cmd.contains(tempPath));
            assertTrue("Command should contain output path", cmd.contains(outputPath));
        }
    }

    return nodeV;
  }

  /**
   * Returns the node that is adjacent to {@code node} along the origin edge.
   *
   * @throws IllegalArgumentException if this {@link EndpointPair} does not contain {@code node}
   * @since 20.0 (but the argument type was changed from {@code Object} to {@code N} in 31.0)
   */
  public final N adjacentNode(N node) {
    if (node.equals(nodeU)) {
      return nodeV;

  public void testPut_nullKeyUnsupported() {
    assertThrows(NullPointerException.class, () -> put(nullKeyEntry));
    expectUnchanged();
    expectNullKeyMissingWhenNullKeysUnsupported(
        "Should not contain null key after unsupported put(null, value)");
  }

  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES})
  public void testPut_nullValueSupported() {

  }

  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));
    }
  }

  /**

But you need `file_path` itself to contain a *path*, like `home/johndoe/myfile.txt`.

So, the URL for that file would be something like: `/files/home/johndoe/myfile.txt`.

### OpenAPI support { #openapi-support }

OpenAPI doesn't support a way to declare a *path parameter* to contain a *path* inside, as that could lead to scenarios that are difficult to test and define.

   * whose elements are the result of applying {@code elementFunction} to the inputs, with counts
   * equal to the result of applying {@code countFunction} to the inputs.
   *
   * <p>If the mapped elements contain duplicates (according to {@code comparator}), the first
   * occurrence in encounter order appears in the resulting multiset, with count equal to the sum of

            assertEquals(2, merged.modifiedPoms().size(), "Should merge modified POMs");
            assertTrue(merged.processedPoms().contains(pom1), "Should contain overlapping POM");
            assertTrue(merged.processedPoms().contains(pom2), "Should contain all POMs");
        }

        @Test
        @DisplayName("should handle merging success and failure results")