Adds an object to the plot in a specified place.

        Args:
            obj (Renderer) : the object to add to the Plot
            place (str, optional) : where to add the object (default: 'center')
                Valid places are: 'left', 'right', 'above', 'below', 'center'.

        Returns:
            None

def add_layout(self, obj, place='center'):
        ''' Adds an object to the plot in a specified place.

        Args:
            obj (Renderer) : the object to add to the Plot
            place (str, optional) : where to add the object (default: 'center')
                Valid places are: 'left', 'right', 'above', 'below', 'center'.

        Returns:
            None

        '''
        valid_places = ['left', 'right', 'above', 'below', 'center']
        if place not in valid_places:
            raise ValueError(
                "Invalid place '%s' specified. Valid place values are: %s" % (place, nice_join(valid_places))
            )

        getattr(self, place).append(obj)