input: Write a function that returns the current date and time formatted as "YYYY-MM-DD HH:MM:SS".
  
  from datetime import datetime
  
  def get_current_date_time():
      current_time = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
      return current_time
  
  assert get_current_date_time() == datetime.now().strftime("%Y-%m-%d %H:%M:%S")
output: 
  def get_current_date_time():
      current_time = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
      return current_time
  