code: private List<Class<?>> loadServiceClasses(ClassLoader loader)
              throws MojoExecutionException {
          List<Class<?>> serviceClasses = new ArrayList<Class<?>>();
          for (String serviceClassName : getServices()) {
              try {
                  Class<?> serviceClass = loader.loadClass(serviceClassName);
                  serviceClasses.add(serviceClass);
              } catch (ClassNotFoundException ex) {
                  throw new MojoExecutionException("Could not load class: " + serviceClassName, ex);
              }
          }
          return serviceClasses;
      }
docs: Loads all interfaces using the provided ClassLoader
  
  @param loader the classloader
  @return thi List of Interface classes
  @throws MojoExecutionException
  is the interfaces are not interfaces or can not be found on
  the classpath