Error of missing bid/ask/bid_size/ask_size from quote result

[Lewissssssss]

Below is an example of symbol SHY, you can see bid/bid_size/ask/ask_size are 0:

symbol: SHY (type: str)
sec_type: 1 (type: int)
tick: N (type: str)
bid: 0 (type: int)
bid_size: 0 (type: int)
ask: 0 (type: int)
ask_size: 0 (type: int)
last: 82.82 (type: float)
change: 0.02 (type: float)
high: 82.84 (type: float)
low: 82.81 (type: float)
bid_mmid: (type: str)
ask_mmid: (type: str)
last_mmid: -NA- (type: str)
last_size: 100 (type: int)
change_color: green (type: str)
vol: 3088472 (type: int)
today_close: 82.82 (type: float)
prev_close: 82.8 (type: float)
show_close: N (type: str)
change_percent: 0.02 (type: float)
margin_long_req: 50 (type: int)
margin_short_req: 50 (type: int)
open: 0 (type: int)
quote_time: 12:46:46 pm (type: str)
last_trade_time: 12:46 pm (type: str)
company_name: iShares 1-3 Year Treasury Bond ETF (type: str)
mssecid: FEUSA00038 (type: str)
exchange: NASDAQ (type: str)
has_option: True (type: bool)
is_etf: True (type: bool)
is_fractional: True (type: bool)
is_overnight: True (type: bool)
realtime: T (type: str)
nls: T (type: str)
shares: 0 (type: int)