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.
docstr: Marks a grid cell as active.
  
  Parameters
  ----------
  elem
      Tuple of grid cell index (column, row)
docstr_tok: ["Marks","a","grid","cell","as","active",".","Parameters","--","--","--","--","--","elem","Tuple","of","grid","cell","index","(","column",",","row",")"]
code: def add(self, elem: Tuple[int, int]):
      """Marks a grid cell as active.
  
      Parameters
      ----------
      elem
          Tuple of grid cell index (column, row)
      """
  
      self.add_range(elem[0], elem[1], elem[1] + 1)
  
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 3 for calling the CRWindow obj's underlying member method code with example usage: obj.add(elem) without return types