input: Write a function to optimize the given objective function using the scipy.optimize.minimize method. The function should set up the optimization problem with an initial guess and return the optimized values.
  assert optimize()==[0.0, 0.0, 0.0]
output: def optimize():
      from scipy.optimize import minimize
      def objective(x):
          return x[0]**2 + x[1]**2 + x[2]**2
      initial_guess = [1, 1, 1]
      result = minimize(objective, initial_guess)
      return result.x