input: def generate_store_item_class(class_name):
      """
      Generate a Python class for an online store item that includes fields for ID, name, price, and description.
      The generated class will have an __init__ method to initialize the attributes and a __str__ method to return
      a formatted string representation of the item. Additionally, it will have a to_dict method to return a dictionary
      representation of the item.
      >>> item = generate_store_item_class('StoreItem')(1, 'Laptop', 999.99, 'High-performance laptop')
      >>> print(item)
      Laptop, $999.99
      >>> item.to_dict()
      {'item_id': 1, 'name': 'Laptop', 'price': 999.99, 'description': 'High-performance laptop'}
      """
      class_definition = 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
          }}
          """
      exec(class_definition, globals())
      return globals()[class_name]
output:     
      class_definition = 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
          }}
          """
      exec(class_definition, globals())
      return globals()[class_name]
  