input: Write a function to create a Python class for an online store item that includes fields for ID, name, price, and description. The class should also include a method to convert the item into a dictionary representation and a string representation.
  
  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', 'Book', 15.99, 'A classic novel')) == 'Book, $15.99'
  assert StoreItem('2', 'Pen', 2.50, 'Blue pen').to_dict() == {'item_id': '2', 'name': 'Pen', 'price': 2.50, 'description': 'Blue pen'}
  assert str(StoreItem('3', 'Notebook', 10.00, 'Large size notebook')) == 'Notebook, $10.00'
  assert StoreItem('4', 'Eraser', 1.25, 'A white eraser').to_dict() == {'item_id': '4', 'name': 'Eraser', 'price': 1.25, 'description': 'A white eraser'}
  assert str(StoreItem('5', 'Stapler', 5.75, 'Heavy-duty stapler')) == 'Stapler, $5.75'
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
          }