input: 
  from typing import List
  
  def perform_crud_operations(model: Model, operations: List[dict]) -> List[tuple]:
      """
      Given an instance of the Model class and a list of CRUD operations, execute these operations 
      in the order they appear and return a list of results for each operation. Each element in the 
      operations list is a dictionary with the following keys:
      - 'operation': One of 'create', 'read', 'update', 'delete'
      - 'data': The data to be used for the operation (relevant for 'create', 'update', and 'delete')
      For 'read' operations, the data field should be None. The function should return a list of 
      tuples, where each tuple is the result of executing the corresponding operation.
  
      Example:
      >>> model = Model()
      >>> operations = [
              {'operation': 'create', 'data': 'Item1'},
              {'operation': 'create', 'data': 'Item2'},
              {'operation': 'read', 'data': None},
              {'operation': 'update', 'data': 'Item3'},
              {'operation': 'read', 'data': None},
              {'operation': 'delete', 'data': 'Item3'},
              {'operation': 'read', 'data': None}
          ]
      >>> perform_crud_operations(model, operations)
      [None, None, [('Item1',), ('Item2',)], None, [('Item3',)], None, []]
      """
  
output:     results = []
      for op in operations:
          if op['operation'] == 'create':
              results.append(model.create(op['data']))
          elif op['operation'] == 'read':
              results.append(model.read())
          elif op['operation'] == 'update':
              results.append(model.update(op['data']))
          elif op['operation'] == 'delete':
              results.append(model.delete(op['data']))
      return results