'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'):

    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))))
    if hasattr(obj, 'plot'):
        if (obj.plot is not None):
            raise ValueError("object    to    be    added    already    has    'plot'    attribute    set")
        obj.plot = self
    self.renderers.append(obj)
    if (place is not 'center'):
        getattr(self, place).append(obj)
