input: Write a python function to retrieve and print all rows from the 'orders' table where the status is 'shipped'.
  assert retrieve_shipped_orders('test_database.db')==[(1, 'order1', 'shipped'), (3, 'order3', 'shipped')]
  assert retrieve_shipped_orders('another_database.db')==[(2, 'order2', 'shipped'), (4, 'order4', 'shipped')]
  assert retrieve_shipped_orders('empty_database.db')==[]
output: import sqlite3
  
  def retrieve_shipped_orders(db_name):
      connection = sqlite3.connect(db_name)
      cursor = connection.cursor()
      
      cursor.execute("SELECT * FROM orders WHERE status = 'shipped'")
      shipped_orders = cursor.fetchall()
      
      connection.close()
      return shipped_orders