code: public function field(string $field, string $inverse = null): self
      {
          $this->defaults = array_merge($this->defaults, [
              ResourceRegistrar::PARAM_RELATIONSHIP_NAME => $field,
              ResourceRegistrar::PARAM_RELATIONSHIP_INVERSE_TYPE => $inverse ?: Str::plural($field),
          ]);
  
          return $this;
      }
docs: Set the route's relationship field name and inverse resource type.
  
  @param string $field
  @param string|null $inverse
  @return $this