code: private boolean hasExpandableVarArgs(IMockMethod method, List<Object> args) {
      List<Class<?>> paramTypes = method.getParameterTypes();
      return !paramTypes.isEmpty()
          && CollectionUtil.getLastElement(paramTypes).isArray()
          && CollectionUtil.getLastElement(args) != null;
    }
docs: Tells if the given method call has expandable varargs. Note that Groovy
  supports vararg syntax for all methods whose last parameter is of array type.