input: def generate_online_store_item_class(class_name: str) -> str:
      """
      Generate a Python class for an online store item that includes fields for ID, name, price, and description.
  
      >>> generate_online_store_item_class('StoreItem')
      class StoreItem:
          def __init__(self, item_id, name, price, description):
              self.item_id = item_id
              self.name = name
              self.price = price
              self.description = description
  
          def __str__(self):
              return f'{self.name}, ${self.price}'
  
          def to_dict(self):
              return {
                  'item_id': self.item_id,
                  'name': self.name,
                  'price': self.price,
                  'description': self.description
              }
      """
output:     return f"""class {class_name}:
      def __init__(self, item_id, name, price, description):
          self.item_id = item_id
          self.name = name
          self.price = price
          self.description = description
  
      def __str__(self):
          return f'{{self.name}}, ${{self.price}}'
  
      def to_dict(self):
          return {{
              'item_id': self.item_id,
              'name': self.name,
              'price': self.price,
              'description': self.description
          }}"""