code: def fib(n):
      """Returns the nth value in the Fibonacci sequence."""
  
      if n <= 2:
          return n
      if n in _fib_cache:
          return _fib_cache[n]
      result = fib(n - 1) + fib(n - 2)
      _fib_cache[n] = result
      return result
  
file_path: whoosh/src/whoosh/util/__init__.py
imports: from __future__ import with_statement
  import random, sys, time
  from bisect import insort
  from functools import wraps
  from whoosh.compat import xrange
label_desc: Use image node_id 5 for calling a global function with example usage: fib(n) and returns: result, n, _fib_cache