class_docstr: Compressed row representation window.
  Stores the range of active grid cells in each column.
  Any window with contiguous columns can be expressed as a CRWindow.
  Supports efficient iterative construction and updates.
code: def column_lengths(self) -> np.ndarray:
      ranges = self.column_ranges
      start = ranges[::2]
      end = ranges[1::2]
  
      return np.maximum(np.subtract(end, start), 0)
  
imports: import array
  from abc import ABC, abstractmethod
  from math import atan, tan
  from typing import Tuple
  import numpy
  from darts.logging import raise_if, raise_if_not
label_desc: Use image node_id 8 for calling the CRWindow obj's underlying member method code with example usage: obj.column_lengths() and returns: np