code: def estimate_bounding_boxes_norm_type(bounding_boxes):
      type_str = estimate_normalization_type(bounding_boxes)
      valid_type_strs = [
          "None",
          "array[float]",
          "array[int]",
          "array[uint]",
          "tuple[number,size=4]",
          "BoundingBox",
          "BoundingBoxesOnImage",
          "iterable[empty]",
          "iterable-array[float]",
          "iterable-array[int]",
          "iterable-array[uint]",
          "iterable-tuple[number,size=4]",
          "iterable-BoundingBox",
          "iterable-BoundingBoxesOnImage",
          "iterable-iterable[empty]",
          "iterable-iterable-tuple[number,size=4]",
          "iterable-iterable-BoundingBox",
      ]
      _assert_is_of_norm_type(
          type_str, valid_type_strs, "bounding_boxes"
      )
      return type_str
  
imports: from __future__ import print_function, division, absolute_import
  import functools
  import numpy
  from ..None import imgaug
  from ..None import dtypes
  from .base import IAugmentable
label_desc: Use image node_id 27 for calling a global function with example usage: estimate_bounding_boxes_norm_type(bounding_boxes) and returns: type_str