code: def set_category(self, category: str = None) -> 'PygalleBaseClass':
          
          return self.set_internal(PygalleBaseClass.__KEYS.CATEGORY, category)
docs: Define the category of the class.
  
          # Arguments
              category: The name of category.
  
          # Returns:
              PygalleBaseClass: An instance of :class:`PygalleBaseClass`