input: Write a Python class for an online store item that includes fields for ID, name, price, and description. Implement methods to return a string representation of the item and a dictionary representation of the item.
  
  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(1, "Laptop", 899.99, "High-performance laptop"))=="Laptop, $899.99"
  assert StoreItem(2, "Keyboard", 29.99, "Mechanical keyboard").to_dict()=={'item_id': 2, 'name': 'Keyboard', 'price': 29.99, 'description': 'Mechanical keyboard'}
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
          }
  