def clean(self):
if self.staffMember and self.staffMember.userAccount andself.user and not self.staffMember.userAccount == self.user:<EOL><INDENT>raise ValidationError(_('<STR_LIT>'))<EOL><DEDENT>if self.location and (self.user or self.staffMember):<EOL><INDENT>raise ValidationError(_('<STR_LIT>'))<EOL><DEDENT>
Verify that the user and staffMember are not mismatched.
Location can only be specified if user and staffMember are not.