code: def _fit_conditional(self):
      self.conditional_density = KDEMultivariateConditional(
          endog=self._data[self._outcome_names],
          exog=self._data[
              self._treatment_names
              + self._target_estimand.get_backdoor_variables()
          ],
          dep_type="".join(self.dep_type),
          indep_type="".join(self.indep_type),
          bw=self.bw,
          defaults=self.defaults,
      )
  
file_path: dowhy/dowhy/do_samplers/kernel_density_sampler.py
imports: import numpy
  from scipy.interpolate import interp1d
  from statsmodels.nonparametric.kernel_density import EstimatorSettings, KDEMultivariateConditional
  from dowhy.do_sampler import DoSampler
label_desc: Use image node_id 2 for calling the KernelDensitySampler obj's underlying member method code with example usage: obj._fit_conditional() without return types