in src/main/java/org/apache/maven/plugins/antrun/AntRunMojo.java [490:500]
public void initMavenTasks(Project antProject) {
getLog().debug("Initializing Maven Ant Tasks");
Typedef typedef = new Typedef();
typedef.setProject(antProject);
typedef.setResource(ANTLIB);
if (getTaskPrefix() != null) {
typedef.setURI(TASK_URI);
}
typedef.execute();
}