def sendBox(self, box):
for k, v in box.iteritems():<EOL><INDENT>if not (isinstance(k, str) and isinstance(v, str)):<EOL><INDENT>raise TypeError("<STR_LIT>")<EOL><DEDENT><DEDENT>self.boxes.append(box)<EOL>
Reject boxes with non-string keys or values; save all the rest in
C{self.boxes}.