code: def fib_recursive(n):
      """[summary]
      Computes the n-th fibonacci number recursive.
      Problem: This implementation is very slow.
      approximate O(2^n)
  
      Arguments:
          n {[int]} -- [description]
  
      Returns:
          [int] -- [description]
      """
  
      # precondition
      assert n >= 0, "n must be a positive integer"
  
      if n <= 1:
          return n
      return fib_recursive(n - 1) + fib_recursive(n - 2)
  
label_desc: Use image node_id 1 for calling a global function with example usage: fib_recursive(n) and returns: unknown, n