code: def sort_key(buffer):
      """Returns a sort key such that "simpler" buffers are smaller than
      "more complicated" ones.
  
      We define sort_key so that x is simpler than y if x is shorter than y or if
      they have the same length and x < y lexicographically. This is called the
      shortlex order.
  
      The reason for using the shortlex order is:
  
      1. If x is shorter than y then that means we had to make fewer decisions
         in constructing the test case when we ran x than we did when we ran y.
      2. If x is the same length as y then replacing a byte with a lower byte
         corresponds to reducing the value of an integer we drew with draw_bits
         towards zero.
      3. We want a total order, and given (2) the natural choices for things of
         the same size are either the lexicographic or colexicographic orders
         (the latter being the lexicographic order of the reverse of the string).
         Because values drawn early in generation potentially get used in more
         places they potentially have a more significant impact on the final
         result, so it makes sense to prioritise reducing earlier values over
         later ones. This makes the lexicographic order the more natural choice.
      """
      return (len(buffer), buffer)
  
imports: from __future__ import absolute_import, division, print_function
  from collections import defaultdict
  import attr
  from hypothesis.internal.compat import hbytes, hrange, int_from_bytes, int_to_bytes
  from hypothesis.internal.conjecture.choicetree import ChoiceTree
  from hypothesis.internal.conjecture.data import ConjectureResult, Overrun, Status
  from hypothesis.internal.conjecture.floats import DRAW_FLOAT_LABEL, float_to_lex, lex_to_float
  from hypothesis.internal.conjecture.junkdrawer import binary_search, replace_all
  from hypothesis.internal.conjecture.shrinking import Float, Integer, Lexical, Ordering
  from hypothesis.internal.conjecture.shrinking.common import find_integer
label_desc: Use image node_id 1 for calling a global function with example usage: sort_key(buffer) and returns: len,  buffer