input: Write a function that creates a Python class named Person with the attributes name, age, and email, and a method toString() which returns a formatted string of these attributes. Then, provide a set of test cases to validate the functionality of the class.
  
  class Person:
      
      def __init__(self, name, age, email):
          self.name = name
          self.age = age
          self.email = email
      
      def toString(self):
          return f"Name: {self.name}, Age: {self.age}, Email: {self.email}"
  
  assert Person("Alice", 30, "alice@example.com").toString()=="Name: Alice, Age: 30, Email: alice@example.com"
  assert Person("Bob", 25, "bob@example.com").toString()=="Name: Bob, Age: 25, Email: bob@example.com"
  assert Person("Charlie", 40, "charlie@example.com").toString()=="Name: Charlie, Age: 40, Email: charlie@example.com"
output: class Person:
      
      def __init__(self, name, age, email):
          self.name = name
          self.age = age
          self.email = email
      
      def toString(self):
          return f"Name: {self.name}, Age: {self.age}, Email: {self.email}"