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_index(self, elem: Tuple[int, int]) -> int:
      i, j = elem
  
      start, end = self.column_ranges[i]
      if j < start or j >= end:
          return -1
      else:
          return j - start
  
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 5 for calling the CRWindow obj's underlying member method code with example usage: obj.column_index(elem) and returns: unknown, unknown