resourceTypesAreTraversable example

'Invalid nested filtering. The field `%s`, given in the path `%s`, does not exist.',
          $part,
          $external_field_name
        ));
      }

      $field_name = $this->getInternalName($part, $resource_types);

      // If none of the resource types are traversable, assume that the       // remaining path parts are targeting field deltas and/or field       // properties.       if (!$this->resourceTypesAreTraversable($resource_types)) {
        $reference_breadcrumbs[] = $field_name;
        return $this->constructInternalPath($reference_breadcrumbs, $parts);
      }

      // Different resource types have different field definitions.       $candidate_definitions = $this->getFieldItemDefinitions($resource_types, $field_name);
      assert(!empty($candidate_definitions));

      // We have a valid field, so add it to the validated trail of path parts.       $reference_breadcrumbs[] = $field_name;