class_docstr: A mock timer producing random (but monotonic) values.
class_docstr_tok: ["A","mock","timer","producing","random","(","but","monotonic",")","values","."]
code: def __call__(self):
      dt = self.random.expovariate(1.0)
      self.last += dt
      self.timings.append(self.last)
      self.durations[next(self.i_durations)].append(dt)
      return self.last
  
file_path: distributed/distributed/tests/test_utils_perf.py
imports: from __future__ import annotations
  import contextlib
  import gc
  import itertools
  import random
  import re
  import pytest
  from distributed.metrics import thread_time
  from distributed.utils_perf import FractionalTimer, GCDiagnosis, disable_gc_diagnosis
  from distributed.utils_test import captured_logger, run_for
label_desc: Use image node_id 2 for calling the RandomTimer obj's underlying member method code with example usage: obj.__call__() and returns: self