input: Write a python function to create an Employee class with attributes name, ID, and salary, and then create an instance of the Employee class.
  assert isinstance(employee, Employee)
  assert employee.name == 'John'
  assert employee.ID == '123456'
  assert employee.salary == 50000
output: def create_employee():
      class Employee:
          def __init__(self, name, ID, salary):
              self.name = name
              self.ID = ID
              self.salary = salary
  
      employee = Employee('John', '123456', 50000)
      return employee