class_docstr: Predefined user-weights ensemble
class_docstr_tok: ["Predefined","user-weights","ensemble"]
code: def ensemble_size(self):
      return len(self.weights_)
  
imports: import logging
  import time
  from collections import Counter
  import numpy
  from ...constants import PROBLEM_TYPES
  from ...metrics import log_loss
  from ...utils import compute_weighted_metric, get_pred_from_proba
label_desc: Use image node_id 2 for calling the SimpleWeightedEnsemble obj's underlying member method code with example usage: obj.ensemble_size() and returns: len