input: Write a python function to create an Employee object, retrieve its full name, and salary.
  assert create_employee("John", "Doe", 10000).get_full_name() == "John Doe"
  assert create_employee("Jane", "Smith", 15000).salary == 15000
  assert create_employee("Alice", "Johnson", 12000).get_full_name() == "Alice Johnson"
output: class Employee:
      def __init__(self, first_name, last_name, salary):
          self.first_name = first_name
          self.last_name = last_name
          self.salary = salary
      
      def get_full_name(self):
          return f"{self.first_name} {self.last_name}"
  
  def create_employee(first_name, last_name, salary):
      return Employee(first_name, last_name, salary)