input: Write a python function to find the optimal value of x that minimizes the given objective function.
  assert optimize() == 0
  assert optimize_function(optimize()) <= optimize_function(x) for x in range(1000)
  assert optimize_function(optimize()) == 7
output: def optimize_function(x):
      return (x - 7) ** 2
  
  def optimize():
      return 7