in maven-plugin-testing-harness/src/main/java/org/apache/maven/plugin/testing/AbstractMojoTestCase.java [294:308]
protected <T extends Mojo> T lookupMojo(String goal, File pom) throws Exception {
File pluginPom = new File(getBasedir(), "pom.xml");
Xpp3Dom pluginPomDom = Xpp3DomBuilder.build(ReaderFactory.newXmlReader(pluginPom));
String artifactId = pluginPomDom.getChild("artifactId").getValue();
String groupId = resolveFromRootThenParent(pluginPomDom, "groupId");
String version = resolveFromRootThenParent(pluginPomDom, "version");
PlexusConfiguration pluginConfiguration = extractPluginConfiguration(artifactId, pom);
return lookupMojo(groupId, artifactId, version, goal, pluginConfiguration);
}