input: Write a function to generate an RSA public/private key pair and save them as files named "public.pem" and "private.pem". The public key should be saved in 'public.pem' and the private key should be saved in 'private.pem'. Use 2048 bits for the key generation.
  
  from Crypto.PublicKey import RSA
  
  def generate_key_pair():
   key = RSA.generate(2048)
   pub_key = key.publickey().export_key().decode()
   with open('public.pem', 'w') as file:
    file.write(pub_key)
   
   priv_key = key.export_key().decode()
   with open('private.pem', 'w') as file:
    file.write(priv_key)
  
  generate_key_pair()
  
  assert generate_key_pair() == None
output: 
  def generate_key_pair():
   key = RSA.generate(2048)
   pub_key = key.publickey().export_key().decode()
   with open('public.pem', 'w') as file:
    file.write(pub_key)
   
   priv_key = key.export_key().decode()
   with open('private.pem', 'w') as file:
    file.write(priv_key)
  