/**
     * Adds the environment variables in the form of properties whose keys are prefixed with {@code env.}, e.g. {@code
     * env.PATH}. Unlike native environment variables, properties are always case-sensitive. For the sake of
     * determinism, the environment variable names will be normalized to upper case on platforms with case-insensitive
     * variable lookup.
     *

     * point at the POM rather than its base directory if the path ends with ".xml" (ignoring case)</li>
     * <li>The name of the child's base directory matches the artifact id of the child.</li>
     * </ul>
     * Note that for the sake of independence from the user
     * environment, the filesystem is intentionally not used for the calculation.</p>
     *
     * @param child The child model, must not be <code>null</code>.