code: def _pts_convert(
      pts, timebase_from, timebase_to, round_func=math.floor
  ):
      """convert pts between different time bases
      Args:
          pts: presentation timestamp, float
          timebase_from: original timebase. Fraction
          timebase_to: new timebase. Fraction
          round_func: rounding function.
      """
      new_pts = Fraction(pts, 1) * timebase_from / timebase_to
      return int(round_func(new_pts))
  
imports: import collections
  import math
  import os
  from fractions import Fraction
  import numpy
  import pytest
  import torch
  import torchvision.io
  from common_utils import assert_equal
  from numpy.random import randint
  from pytest import approx
  from torchvision import set_video_backend
  from torchvision.io import _HAS_VIDEO_OPT
label_desc: Use image node_id 5 for calling a global function with example usage: _pts_convert(pts, timebase_from, timebase_to, round_func) and returns: int