How to use the lektor.db._BinExpr function in Lektor

def endswith_cs(self, other):
        return _BinExpr(self, _auto_wrap_expr(other),
                        lambda a, b: unicode(a).endswith(unicode(b)))

def __and__(self, other):
        return _BinExpr(self, _auto_wrap_expr(other), operator.and_)

def endswith(self, other):
        return _BinExpr(self, _auto_wrap_expr(other),
            lambda a, b: text_type(a).lower().endswith(text_type(b).lower()))

def __eq__(self, other):
        return _BinExpr(self, _auto_wrap_expr(other), operator.eq)

def endswith(self, other):
        return _BinExpr(self, _auto_wrap_expr(other),
            lambda a, b: unicode(a).lower().endswith(unicode(b).lower()))

def __or__(self, other):
        return _BinExpr(self, _auto_wrap_expr(other), operator.or_)

def startswith(self, other):
        return _BinExpr(self, _auto_wrap_expr(other),
            lambda a, b: unicode(a).lower().startswith(unicode(b).lower()))

def __eq__(self, other):
        return _BinExpr(self, _auto_wrap_expr(other), operator.eq)

def startswith(self, other):
        return _BinExpr(self, _auto_wrap_expr(other),
            lambda a, b: text_type(a).lower().startswith(text_type(b).lower()))

def __gt__(self, other):
        return _BinExpr(self, _auto_wrap_expr(other), operator.gt)