#NEWLINE# def two_factor_auth_callback( self , callback ) : #NEWLINE# #INDENT# if ( not callback ) : #NEWLINE# #INDENT# return #NEWLINE# #UNINDENT# if ( not isinstance ( callback , Callable ) ) : #NEWLINE# #INDENT# raise ValueError ( 'Your callback should be callable' ) #NEWLINE# #UNINDENT# self . two_factor_auth_cb = self