class_docstr: Base class for histogram-based gradient boosting estimators.
class_docstr_tok: ["Base","class","for","histogram-based","gradient","boosting","estimators","."]
docstr: Validate parameters passed to __init__.
  
  The parameters that are directly passed to the grower are checked in
  TreeGrower.
docstr_tok: ["Validate","parameters","passed","to","__init__",".","The","parameters","that","are","directly","passed","to","the","grower","are","checked","in","TreeGrower","."]
code: def _validate_parameters(self):
      """Validate parameters passed to __init__.
  
      The parameters that are directly passed to the grower are checked in
      TreeGrower."""
      if (
          self.monotonic_cst is not None
          and self.n_trees_per_iteration_ != 1
      ):
          raise ValueError(
              "monotonic constraints are not supported for multiclass classification."
          )
  
imports: import itertools
  from abc import ABC, abstractmethod
  from functools import partial
  from numbers import Integral, Real
  from timeit import default_timer
  import numpy
  from ..._loss.loss import _LOSSES, BaseLoss, HalfBinomialLoss, HalfGammaLoss, HalfMultinomialLoss, HalfPoissonLoss, PinballLoss
  from ...base import BaseEstimator, ClassifierMixin, RegressorMixin, _fit_context, is_classifier
  from ...metrics import check_scoring
  from ...model_selection import train_test_split
  from ...preprocessing import LabelEncoder
  from ...utils import check_random_state, compute_sample_weight, resample
  from ...utils._openmp_helpers import _openmp_effective_n_threads
  from ...utils._param_validation import Interval, RealNotInt, StrOptions
  from ...utils.multiclass import check_classification_targets
  from ...utils.validation import _check_monotonic_cst, _check_sample_weight, check_consistent_length, check_is_fitted
  from ._gradient_boosting import _update_raw_predictions
  from .binning import _BinMapper
  from .common import G_H_DTYPE, X_DTYPE, Y_DTYPE
  from .grower import TreeGrower
label_desc: Use image node_id 2 for calling the BaseHistGradientBoosting obj's underlying member method code with example usage: obj._validate_parameters() without return types