code: def max_value_of_column(self, i: int):
      if self._max_value_cache[i] is None:
          self._max_value_cache[i] = self.get_column(i).max()
      return self._max_value_cache[i]
  
imports: from operator import gt, le
  from typing import Any, List, Optional, Union
  import numpy
  import pandas
  from .errors import NoSplittableVariableException
  from .splitcondition import SplitCondition
label_desc: Use image node_id 10 for calling the CovariateMatrix obj's underlying member method code with example usage: obj.max_value_of_column(i) and returns: self