This attribute holds a string which is used as a title in (e.g.)
graphical output to describe the coordinate system which a Frame
represents. Examples might be "Detector Coordinates" or
If a Title value has not been set for a Frame, then a suitable
default is supplied, depending on the class of the Frame.
The default supplied by the Frame class is "n-d coordinate
system", where n is the number of Frame axes (Naxes