class_docstr: Abstract class representing a coordinate transformation.
  
  Detections' and tracked objects' coordinates can be interpreted in 2 reference:
  
  - _Relative_: their position on the current frame, (0, 0) is top left
  - _Absolute_: their position on an fixed space, (0, 0)
      is the top left of the first frame of the video.
  
  Therefore, coordinate transformation in this context is a class that can transform
  coordinates in one reference to another.
code: def abs_to_rel(self, points: np.ndarray) -> np.ndarray:
      pass
  
imports: from abc import ABC, abstractmethod
  from typing import Optional, Tuple
  import numpy
label_desc: Use image node_id 1 for calling the CoordinatesTransformation obj's underlying member method code with example usage: obj.abs_to_rel(points) without return types