How to use the sqlobject.converters.sqlrepr function in SQLObject

def __sqlrepr__(self, db):
        fieldName = self.fieldName
        if isinstance(fieldName, SQLExpression):
            fieldName = sqlrepr(fieldName, db)
        return self.alias + "." + fieldName

def PostgresBinaryConverter(value, db):
    assert db == 'postgres'
    return sqlrepr(escape_bytea(value), db)

select += " %s" % _str_or_sqlrepr(self.ops['items'][0], db)

        join = []
        join_str = ''
        if self.ops['join'] is not NoDefault and self.ops['join'] is not None:
            _join = self.ops['join']
            if isinstance(_join, str):
                join_str = " " + _join
            elif isinstance(_join, SQLJoin):
                join.append(_join)
            else:
                join.extend(_join)
        tables = set()
        for x in self.ops['staticTables']:
            if isinstance(x, SQLExpression):
                x = sqlrepr(x, db)
            tables.add(x)
        things = list(self.ops['items']) + join
        if self.ops['clause'] is not NoDefault:
            things.append(self.ops['clause'])
        for thing in things:
            if isinstance(thing, SQLExpression):
                tables.update(tablesUsedSet(thing, db))
        for j in join:
            t1 = _str_or_sqlrepr(j.table1, db)
            if t1 in tables:
                tables.remove(t1)
            t2 = _str_or_sqlrepr(j.table2, db)
            if t2 in tables:
                tables.remove(t2)
        if tables:
            select += " FROM %s" % ", ".join(sorted(tables))

def __sqlrepr__(self, db):
        if self.proxy.soClass is None:
            return '_DELAYED_' + self.attr
        val = self._resolve()
        if isinstance(val, SQLExpression):
            val = sqlrepr(val, db)
        return val

join = "%s %s ON %s" % (self.op, sqlrepr(self.table2, db),
                                    on_condition)
            if self.table1:
                join = "%s %s" % (sqlrepr(self.table1, db), join)
            return join
        elif self.using_columns:
            using_columns = []
            for col in self.using_columns:
                if hasattr(col, "__sqlrepr__"):
                    col = sqlrepr(col, db)
                using_columns.append(col)
            using_columns = ", ".join(using_columns)
            join = "%s %s USING (%s)" % (self.op, sqlrepr(self.table2, db),
                                         using_columns)
            if self.table1:
                join = "%s %s" % (sqlrepr(self.table1, db), join)
            return join
        else:
            RuntimeError, "Impossible error"

def __sqlrepr__(self, db):
        return "(%s %s (%s))" % (
            sqlrepr(self.expr, db), self._get_op(db), sqlrepr(self.string, db)
        )

def __sqlrepr__(self, db):
        return "%s (%s)" % (self.op, sqlrepr(self.subquery, db))

def __sqlrepr__(self, db):
        return " UNION ".join([str(sqlrepr(t, db)) for t in self.tables])

def __sqlrepr__(self, db):
        update = "%s %s" % (self.sqlName(), self.table)
        update += " SET"
        first = True
        if self.template is not NoDefault:
            for i in range(len(self.template)):
                if first:
                    first = False
                else:
                    update += ","
                update += " %s=%s" % (self.template[i],
                                      sqlrepr(self.values[i], db))
        else:
            for key, value in sorted(self.values.items()):
                if first:
                    first = False
                else:
                    update += ","
                update += " %s=%s" % (key, sqlrepr(value, db))
        if self.whereClause is not NoDefault:
            update += " WHERE %s" % _str_or_sqlrepr(self.whereClause, db)
        return update

def tablesUsedSet(self, db):
        tables = set()
        for table in self.tablesUsedImmediate():
            if hasattr(table, '__sqlrepr__'):
                table = sqlrepr(table, db)
            tables.add(table)
        for component in self.components():
            tables.update(tablesUsedSet(component, db))
        return tables