* <p>Many operations can be performed directly using DomTrip's Element API:
 * <pre>{@code
 * // Find child element
 * Element child = parent.child("version").orElse(null);
 *
 * // Check if child exists
 * boolean hasVersion = parent.child("version").isPresent();
 *
 * // Get child text content
 * String version = parent.child("version")
 *     .map(Element::textContent)
 *     .orElse(null);
 *
 * // Get trimmed text content

     *
     * @param child The child model, must not be <code>null</code>.
     * @param parent The parent model, may be <code>null</code>.
     * @param childDirectory The directory defined in child model, may be <code>null</code>.
     * @return The path adjustment, can be empty but never <code>null</code>.
     */
    private String getChildPathAdjustment(Model child, Model parent, String childDirectory) {

        // Test with normal URLs
        String parentUrl = "http://example.com/parent";
        String url = "http://example.com/child";
        ContentNotFoundException exception = new ContentNotFoundException(parentUrl, url);

        assertNotNull(exception);
        assertEquals("Not Found: http://example.com/child Parent: http://example.com/parent", exception.getMessage());
        assertNull(exception.getCause());
    }

    @Test

  <url>http://www.apache.org/child/</url>
  <scm>
    <connection>scm:my-scm:http://domain.org/base/child</connection>
    <developerConnection>scm:my-scm:https://domain.org/base/child/</developerConnection>
    <url>https://domain.org/base/child</url>
  </scm>
  <distributionManagement>
    <site>
      <url>scp://scp.domain.org/base/child/</url>
    </site>
  </distributionManagement>

  <name>Model urls inheritance test child</name>
  <description>MNG-5951 MNG-6059 child.x.y.inherit.append.path="false" for each url to avoid automatic path addition when inheriting</description>

  <!-- 5 inherited urls without anything added to parent -->
  <url>http://www.apache.org/path/to/parent/</url>
  <scm child.scm.connection.inherit.append.path="false"
       child.scm.developerConnection.inherit.append.path="false"

                Stream.of(
                                new DependencyContainer(root.child(DEPENDENCIES).orElse(null), DEPENDENCIES),
                                new DependencyContainer(
                                        root.child(DEPENDENCY_MANAGEMENT)
                                                .flatMap(dm -> dm.child(DEPENDENCIES))
                                                .orElse(null),

  </modules>

  <!-- 5 urls in the pom to configure for not adding path -->
  <url>http://www.apache.org/path/to/parent/</url>
  <scm child.scm.connection.inherit.append.path="false"
       child.scm.developerConnection.inherit.append.path="false"
       child.scm.url.inherit.append.path="false">
    <connection>scm:my-scm:http://domain.org/base</connection>

    /**
     * Merges values from the specified parent model into the given child model. Implementations are expected to keep
     * parent and child completely decoupled by injecting deep copies of objects into the child rather than the original
     * objects from the parent.
     *
     * @param child The child model into which to merge the values inherited from the parent, must not be
     *            <code>null</code>.

            <parent>child</parent>
            <child>child</child>
            <parent-only>parent</parent-only>
          </defaults>
          <appends combine.children="append">
            <parent-only>parent</parent-only>
            <parent>parent</parent>
            <parent>child</parent>
            <child>child</child>
          </appends>
          <overrides combine.self="override">

     * {@code null} to indicate no required children.
     */
    default String requiredChildKey() {
        return null;
    }

    /**
     * @param child a node on which the transformation will be applied.
     * @return true if the transformation should be applied on child node, otherwise false.
     */