code: def __call__(self, x: tp.ArrayLike) -> float:
      return self._func(x)
  
imports: from math import exp, sqrt, tanh
  import numpy
  import nevergrad.common.typing
  from nevergrad.common.decorators import Registry
label_desc: Use image node_id 2 for calling the DiscreteFunction obj's underlying member method code with example usage: obj.__call__(x) and returns: self