input: Write a function to generate a Python class for an online store item that includes fields for ID, name, price, and description. The class should have an initializer (__init__) to set these fields, a __str__ method to return a string representation of the item, and a to_dict method to convert the item to a dictionary.
  
  
  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
          }
  
  item = StoreItem(1, 'Laptop', 999.99, 'A powerful laptop for professionals')
  assert str(item) == 'Laptop, $999.99'
  assert item.to_dict() == {
      'item_id': 1,
      'name': 'Laptop',
      'price': 999.99,
      'description': 'A powerful laptop for professionals'
  }
  
output: 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
          }