docs: def first_true(iterable, default=False, pred=None):
      """Returns the first true value in the iterable.
  
      If no true value is found, returns *default*
  
      If *pred* is not None, returns the first item
      for which pred(item) is true.
  
      """
      # first_true([a,b,c], x) --> a or b or c or x
      # first_true([a,b], x, f) --> a if f(a) else b if f(b) else x
      return next(filter(pred, iterable), default)