code: private void addClassesToClasspath( UnpackedLibHelper helper, MavenProject project, Artifact artifact )
          throws MavenExecutionException
      {
          // Work out where the dep will be extracted and calculate the file path to the classes jar.
          // This is location where the GenerateSourcesMojo will extract the classes.
          final File classesJar = helper.getUnpackedClassesJar( artifact );
          log.debug( "Adding to classpath : " + classesJar );
  
          // In order to satisfy the LifecycleDependencyResolver on execution up to a phase that
          // has a Mojo requiring dependency resolution I need to create a dummy classesJar here.
          if ( !classesJar.exists() )
          {
              classesJar.getParentFile().mkdirs();
              try
              {
                  final ZipOutputStream zipOutputStream = new ZipOutputStream( new FileOutputStream( classesJar ) );
                  zipOutputStream.putNextEntry( new ZipEntry( "dummy" ) );
                  zipOutputStream.close();
                  log.debug( "Created dummy " + classesJar.getName() + " exist=" + classesJar.exists() );
              }
              catch ( IOException e )
              {
                  throw new MavenExecutionException( "Could not add " + classesJar.getName() + " as dependency", e );
              }
          }
  
          
          // Modify the classpath to use an extracted dex file.  This will overwrite
          // any exisiting dependencies with the same information.
          final Dependency dependency = createSystemScopeDependency( artifact, classesJar, null );
          final Dependency providedJar = findProvidedDependencies( dependency, project );
          if ( providedJar != null ) 
          {
              project.getModel().removeDependency( providedJar );
          }
          project.getModel().addDependency( dependency );
      }
docs: Add the dependent library classes to the project classpath.