def isreference(a):
return False<EOL>return id(a) != id(copy.copy(a))<EOL>check = ('<STR_LIT>', '<STR_LIT>')<EOL>for attr in check:<EOL><INDENT>try:<EOL><INDENT>getattr(a, attr)<EOL><DEDENT>except (SystemExit, KeyboardInterrupt):<EOL><INDENT>raise<EOL><DEDENT>except:<EOL><INDENT>pass<EOL><DEDENT>else:<EOL><INDENT>return True<EOL><DEDENT><DEDENT>return False<EOL>
Tell whether a variable is an object reference.

Due to garbage collection, some objects happen to get the id of a distinct variable.
As a consequence, linking is not ready yet and `isreference` returns ``False``.