class_docstr: Base class for transforms implementing a forward and a backward (inverse)
  method.
  This provide a default representation, and a short representation should be implemented
  for each transform.
class_docstr_tok: ["Base","class","for","transforms","implementing","a","forward","and","a","backward","(","inverse",")","method",".","This","provide","a","default","representation",",","and","a","short","representation","should","be","implemented","for","each","transform","."]
code: def backward(self, y: np.ndarray) -> np.ndarray:
      raise NotImplementedError
  
imports: import uuid
  import itertools
  import numpy
  from scipy import stats
  import nevergrad.common.typing
  from .None import utils
label_desc: Use image node_id 3 for calling the Transform obj's underlying member method code with example usage: obj.backward(y) without return types