code: def onepoint(self, donor: np.ndarray, individual: np.ndarray) -> None:
      R = self.random_state.randint(1, donor.size)
      if self.random_state.choice([True, False]):
          donor[R:] = individual[R:]
      else:
          donor[:R] = individual[:R]
  
imports: import warnings
  import numpy
  import nevergrad.common.typing
  from nevergrad.parametrization import parameter
  from .None import metamodel
  from .None import base
  from .None import oneshot
label_desc: Use image node_id 4 for calling the Crossover obj's underlying member method code with example usage: obj.onepoint(donor, individual) without return types