text: from eliot import log_call, to_file
  import sys
  to_file(open("out.log", "w"))
  
  @log_call
  def double(a):
      if a == 0:
          import time
          time.sleep(10)
      return a * 2
  
  @log_call
  def main():
      double(13)
      double(0)
      double(4)
  
  main()
  