code: def to_float(img, max_value=None):
      if max_value is None:
          try:
              max_value = MAX_VALUES_BY_DTYPE[img.dtype]
          except KeyError:
              raise RuntimeError(
                  "Can't infer the maximum value for dtype {}. You need to specify the maximum value manually by "
                  "passing the max_value argument".format(img.dtype)
              )
      return img.astype("float32") / max_value
  
imports: from __future__ import division
  from typing import Optional, Sequence, Union
  from warnings import warn
  import cv2
  import numpy
  import skimage
  from albumentations import random_utils
  from albumentations.augmentations.utils import MAX_VALUES_BY_DTYPE, _maybe_process_in_chunks, clip, clipped, ensure_contiguous, is_grayscale_image, is_rgb_image, non_rgb_warning, preserve_channel_dim, preserve_shape
label_desc: Use image node_id 38 for calling a global function with example usage: to_float(img, max_value) and returns: unknown