input: Write a function to create a Python class for an online store item that includes fields for ID, name, price, and description, along with methods to return a string representation of the item and to return a dictionary of the item's attributes. The class should be named 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
          }
  
  assert str(StoreItem('123', 'Laptop', 999.99, 'High-end gaming laptop')) == 'Laptop, $999.99'
  assert StoreItem('456', 'Mouse', 29.99, 'Ergonomic wireless mouse').to_dict() == {'item_id': '456', 'name': 'Mouse', 'price': 29.99, 'description': 'Ergonomic wireless mouse'}
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
          }