public Class<?> getProxyClass(final Class<?>... classObjs) {
    IllegalArgumentException ex = null;

    for (ClassLoader classLoader : getClassLoaders()) {
      try {
        return Proxy.getProxyClass(classLoader, classObjs);
      } catch (SecurityException sex) {
        // Continue to next classloader
      } catch (IllegalArgumentException iaex) {
        ex = iaex;
        // Continue to next classloader
      }
    }

    if (ex != null) {
      throw ex;
    }
    return null;
  }
See {@link Proxy#getProxyClass(ClassLoader, Class...)}
geode-deployment/geode-deployment-legacy/src/main/java/org/apache/geode/classloader/internal/LegacyClasspathServiceImpl.java