input: Write a Python class for an online store item that includes fields for ID, name, price, and description. Additionally, include methods to get a string representation of the item and to convert the item to a dictionary format.
  
  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', 1000, 'High-end gaming laptop')) == 'Laptop, $1000'
  assert str(StoreItem(2, 'Mouse', 20, 'Wireless gaming mouse')) == 'Mouse, $20'
  assert StoreItem(3, 'Keyboard', 50, 'Mechanical gaming keyboard').to_dict() == {
      'item_id': 3,
      'name': 'Keyboard',
      'price': 50,
      'description': 'Mechanical gaming keyboard'
  }
  assert StoreItem(4, 'Monitor', 300, '24-inch 144Hz gaming monitor').to_dict() == {
      'item_id': 4,
      'name': 'Monitor',
      'price': 300,
      'description': '24-inch 144Hz gaming monitor'
  }
output: 
  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
      }
  