class_docstr: Loss function used in binary classification tasks.
class_docstr_tok: ["Loss","function","used","in","binary","classification","tasks","."]
code: def transfer(self, y):
      return 1.0 / (1.0 + math.exp(-y))
  
file_path: river/river/tree/losses.py
imports: from __future__ import annotations
  import abc
  import math
  from .utils import GradHess
label_desc: Use image node_id 2 for calling the BinaryCrossEntropyLoss obj's underlying member method code with example usage: obj.transfer(y) and returns: unknown