input: Write a python function to create an Employee object and display its details.
  assert create_employee("John", 30, "HR").display() == "Name: John\nAge: 30\nDepartment: HR"
  assert create_employee("Alice", 25, "Engineering").display() == "Name: Alice\nAge: 25\nDepartment: Engineering"
  assert create_employee("Bob", 40, "Sales").display() == "Name: Bob\nAge: 40\nDepartment: Sales"
output: def create_employee(name, age, department):
      class Employee:
          def __init__(self, name, age, department):
              self.name = name
              self.age = age
              self.department = department
  
          def display(self):
              return f"Name: {self.name}\nAge: {self.age}\nDepartment: {self.department}"
  
      return Employee(name, age, department)