Is piece of code in StrPrinter ever reachable?

[Paul Royik]

In StrPrinter there is 

def emptyPrinter(self, expr):
if isinstance(expr, str):
return expr
elif isinstance(expr, Basic):
return repr(expr)
else:
return str(expr)

Is `return repr(expr)` reachable if `StrPrinter` defines `_print_Basic` that prints all `Basic` objects? 

[Oscar Benjamin]

Non-Basic objects can also be printed using the printers. They just
need to inherit Printable (which is a superclass of Basic).


Oscar