// "C:foo" ("C:" - working dir of drive C on Windows)
      return parent;
    }

    // Paths that don't have a parent:
    if (path.getNameCount() == 0) {
      // "/", "C:\", "\" (no parent)
      // "" (undefined, though typically parent of working dir)
      // "C:" (parent of working dir of drive C on Windows)
      //
      // For working dir paths ("" and "C:"), return null because:

            throws ModelBuildingException {
        problems.setSource(childModel);

        Parent parent = childModel.getParent();

        String groupId = parent.getGroupId();
        String artifactId = parent.getArtifactId();
        String version = parent.getVersion();

        ModelResolver modelResolver = request.getModelResolver();
        Objects.requireNonNull(

			return nil
		}
	}

	// Slow path: make sure parent exists and then call Mkdir for path.
	i := len(dirPath)
	for i > 0 && os.IsPathSeparator(dirPath[i-1]) { // Skip trailing path separator.
		i--
	}

	j := i
	for j > 0 && !os.IsPathSeparator(dirPath[j-1]) { // Scan backward over element.
		j--
	}

	if j > 1 {
		// Create parent.
		if err := osMkdirAll(dirPath[:j-1], perm, baseDir); err != nil {

  It is done in <<<InheritanceAssembler>>> ({{{./apidocs/org/apache/maven/model/inheritance/InheritanceAssembler.html}javadoc}}),
  with its <<<DefaultInheritanceAssembler>>> implementation
  ({{{./xref/org/apache/maven/model/inheritance/DefaultInheritanceAssembler.html}source}}).

import com.google.common.base.CaseFormat;

public class ParamMap<K, V> implements Map<K, V> {

    private final Map<K, V> parent;

    public ParamMap(final Map<K, V> parent) {
        this.parent = parent;
    }

    public Map<K, V> getParent() {
        return parent;
    }

    protected Object toCamelCase(final Object key) {
        if (key == null) {
            return key;
        }

            <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>

        }

        @Override
        public Object[] toArray() {
            return parent.toArray();
        }

        @Override
        public <T> T[] toArray(final T[] a) {
            return parent.toArray(a);
        }

        @Override
        public boolean add(final E e) {
            return parent.add(e);
        }

        @Override

                "Expected 'UnresolvableModelException' not thrown.");
        assertEquals("The requested parent version range '[1.0,)' does not specify an upper bound", e.getMessage());
    }

    @Test
    void testResolveParentSuccessfullyResolvesExistingParentWithoutRange() throws Exception {
        final Parent parent = Parent.newBuilder()

            <root>
                <mxCell id="0"/>
                <mxCell id="1" parent="0"/>
                <mxCell id="2" value="" style="rounded=0;whiteSpace=wrap;html=1;fontStyle=1;strokeWidth=4;" parent="1" vertex="1">
                    <mxGeometry x="420" y="280" width="920" height="670" as="geometry"/>
                </mxCell>

            <root>
                <mxCell id="0"/>
                <mxCell id="1" parent="0"/>
                <mxCell id="2" value="" style="rounded=0;whiteSpace=wrap;html=1;fontStyle=1;strokeWidth=4;" parent="1" vertex="1">
                    <mxGeometry x="450" y="-50" width="820" height="970" as="geometry"/>
                </mxCell>