code: def onemax(self, x: tp.ArrayLike) -> float:
      diff = np.round(x) - (np.arange(len(x)) % self._arity)
      return float(np.sum(diff != 0))
  
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 3 for calling the DiscreteFunction obj's underlying member method code with example usage: obj.onemax(x) and returns: float