def _pv_respond_to(opts, key, method_name_list)
        value = _pv_opts_lookup(opts, key)
        unless value.nil?
          Array(method_name_list).each do |method_name|
            unless value.respond_to?(method_name)
              raise ValidationFailed, "Option #{key} must have a #{method_name} method!"
            end
          end
        end
      end
def _pv_respond_to(opts, key, method_name_list)
        value = _pv_opts_lookup(opts, key)
        unless value.nil?
          Array(method_name_list).each do |method_name|
            unless value.respond_to?(method_name)
              raise ValidationFailed, "Option #{key} must have a #{method_name} method!"
            end
          end
        end
      end
Raise an exception if the parameter does not respond to a given set of methods.