docstr: Build decision tree classifier.
docstr_tok: ["Build","decision","tree","classifier","."]
code: def fit(self, X, y):
      """Build decision tree classifier."""
      self.n_classes_ = len(
          set(y)
      )  # classes are assumed to go from 0 to n-1
      self.n_features_ = X.shape[1]
      self.tree_ = self._grow_tree(X, y)
  
imports: import numpy
  import ray
  from sklearn import datasets, metrics
  import time
  import tempfile
  import os
  import json
label_desc: Use image node_id 2 for calling the DecisionTreeClassifier obj's underlying member method code with example usage: obj.fit(X, y) without return types