input: Write a python function to fetch orders from the database that match the current year.
  assert len(fetch_orders()) > 0  # Assuming there are orders for the current year
  assert isinstance(fetch_orders()[0], tuple)  # Assuming the fetched results are tuples
output: import sqlite3
  from datetime import datetime
  
  def fetch_orders():
      current_year = datetime.now().year
      conn = sqlite3.connect('orders.db')
      cursor = conn.cursor()
      query = "SELECT * FROM orders WHERE strftime('%Y', order_date) = ?"
      cursor.execute(query, (str(current_year),))
      orders = cursor.fetchall()
      conn.close()
      return orders