code: def singular_subresource(raml_resource, route_name):
      
      static_parent = get_static_parent(raml_resource, method='POST')
      if static_parent is None:
          return False
      schema = resource_schema(static_parent) or {}
      properties = schema.get('properties', {})
      if route_name not in properties:
          return False
  
      db_settings = properties[route_name].get('_db_settings', {})
      is_obj = db_settings.get('type') == 'relationship'
      single_obj = not db_settings.get('uselist', True)
      return is_obj and single_obj
docs: Determine if :raml_resource: is a singular subresource.
  
      :param raml_resource: Instance of ramlfications.raml.ResourceNode.
      :param route_name: Name of the :raml_resource:.