/*
 * call-seq:
 *   method.origin_class => Class
 *
 * Given a Method, returns the Class in which the method it represents
 * was defined.  If the method was defined in a base class and
 * Object#method is called on a derived instance of that base class,
 * this method returns the base class.
 */
static VALUE method_origin_class(VALUE method)
{
  struct METHOD * m;
  Data_Get_Struct(method, struct METHOD, m);
  return METHOD_OCLASS(m);
}