code: def selection_strategy(oasis_obj, strategy='spectral-oasis', nsel=1, neig=None):
      
      strategy = strategy.lower()
      if strategy == 'random':
          return SelectionStrategyRandom(oasis_obj, strategy, nsel=nsel, neig=neig)
      elif strategy == 'oasis':
          return SelectionStrategyOasis(oasis_obj, strategy, nsel=nsel, neig=neig)
      elif strategy == 'spectral-oasis':
          return SelectionStrategySpectralOasis(oasis_obj, strategy, nsel=nsel, neig=neig)
      else:
          raise ValueError('Selected strategy is unknown: '+str(strategy))
docs: Factory for selection strategy object
  
      Returns
      -------
      selstr : SelectionStrategy
          Selection strategy object