def addWHERE(self, where, boolean=None):
        if where is None:
            return

        if self.WHERE is None:
            self.WHERE = where
        else:
            # if boolean is None:
            #     raise RuntimeError("Must provide boolean instruction to WHERE")
            if boolean != "OR" and boolean != "AND":
                raise RuntimeError("Boolean instruction must OR or AND")
            self.WHERE = "({} {} {})".format(self.WHERE, boolean, where)

        # self.WHERE.append(where)