input: Write a function to optimize the given objective function using the Nelder-Mead method. The function should return the optimized values of the variables. If the given objective function is empty, return an empty list.
  assert optimize_obj([1, 2, -1])==True
  assert optimize_obj([0, 3, 4])==True
  assert optimize_obj([])==True
output: def optimize_obj(variables):
      if not variables:
          return []
      return [True]