code: def n_splittable_variables(self) -> int:
      return len(self.splittable_variables())
  
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 6 for calling the CovariateMatrix obj's underlying member method code with example usage: obj.n_splittable_variables() and returns: len