input: def generate_online_store_item_class() -> str:
      """Generate a Python class for an online store item that includes fields for ID, name, price, and description. 
      The class should have an __init__ method to initialize these fields, a __str__ method to return a string representation 
      of the item (e.g., "Apple, $1.5"), and a to_dict method that returns a dictionary with the item's details.
      Example:
      for generate_online_store_item_class() == 'class StoreItem:\n    def __init__(self, item_id, name, price, description):\n        self.item_id = item_id\n        self.name = name\n        self.price = price\n        self.description = description\n\n    def __str__(self):\n        return f'{self.name}, ${self.price}'\n\n    def to_dict(self):\n        return {\n            'item_id': self.item_id,\n            'name': self.name,\n            'price': self.price,\n            'description': self.description\n        }'
      """
output:     return '''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
          }'''