class_docstr: Isotonic Regression
class_docstr_tok: ["Isotonic","Regression"]
docstr: Id of the validation data frame.
  
  Type: ``Union[None, str, H2OFrame]``.
docstr_tok: ["Id","of","the","validation","data","frame",".","Type",":","``","Union","[","None",",","str",",","H2OFrame","]","``","."]
code: def validation_frame(self):
      """
      Id of the validation data frame.
  
      Type: ``Union[None, str, H2OFrame]``.
      """
      return self._parms.get("validation_frame")
  
imports: from h2o.estimators.estimator_base import H2OEstimator
  from h2o.exceptions import H2OValueError
  from h2o.frame import H2OFrame
  from h2o.utils.typechecks import assert_is_type, Enum, numeric
label_desc: Use image node_id 4 for calling the H2OIsotonicRegressionEstimator obj's underlying member method code with example usage: obj.validation_frame() and returns: self