docstr: Set the percentile of features to return after fitting.
docstr_tok: ["Set","the","percentile","of","features","to","return","after","fitting","."]
code: def set_top_percentile(self, percentile, groups=None):
      """
      Set the percentile of features to return after fitting.
      """
      self._get_support_mask()
      assert (
          percentile <= 1 and percentile >= 0
      ), "percentile must between 0 and 1 inclusive"
      self.n_features = int(self.scores_.shape[0] * percentile)
      return self._set_top_features(groups=groups)
  
imports: import time
  import numpy
  import pandas
  from sklearn.base import BaseEstimator
  from sklearn.feature_selection import SelectorMixin
  from sklearn.utils.validation import check_is_fitted
  import torch
  from nni.feature_engineering.feature_selector import FeatureSelector
  from .None import constants
  from .fginitialize import PrepareData
  from .fgtrain import _train
label_desc: Use image node_id 21 for calling the FeatureGradientSelector obj's underlying member method code with example usage: obj.set_top_percentile(percentile, groups) and returns: self