code: def x10(self, feature):
          
          x10_product = None
          for product in self._x10_products:
              if feature.lower() == product.feature:
                  x10_product = product
  
          if not x10_product:
              x10_product = X10Product(feature, None)
  
          return x10_product
docs: Return an X10 device based on a feature.
  
          Current features:
          - OnOff
          - Dimmable