How to use the zvt.api.business.get_trader function in zvt

self.init_selectors(entity_ids=entity_ids, entity_type=self.entity_type, exchanges=self.exchanges,
                            codes=self.codes, start_timestamp=self.start_timestamp, end_timestamp=self.end_timestamp)

        self.selectors_comparator = self.init_selectors_comparator()

        self.trading_level_asc = list(set([IntervalLevel(selector.level) for selector in self.selectors]))
        self.trading_level_asc.sort()

        self.trading_level_desc = list(self.trading_level_asc)
        self.trading_level_desc.reverse()

        self.targets_slot: TargetsSlot = TargetsSlot()

        self.session = get_db_session('zvt', 'business')
        trader = get_trader(session=self.session, trader_name=self.trader_name, return_type='domain', limit=1)

        if trader:
            self.logger.warning("trader:{} has run before,old result would be deleted".format(self.trader_name))
            self.session.query(business.Trader).filter(business.Trader.trader_name == self.trader_name).delete()
            self.session.commit()
        self.on_start()

def load_traders():
    global trader_domains
    global trader_names

    trader_domains = get_trader(return_type='domain')
    for trader in trader_domains:
        account_readers.append(AccountReader(trader_names=[trader.trader_name], level=trader.level))
        order_readers.append(OrderReader(trader_names=[trader.trader_name]))

    trader_names = [item.trader_name for item in trader_domains]

import dash
import dash_core_components as dcc
import dash_daq as daq
import dash_html_components as html
from dash.dependencies import Input, Output

from zvt.api.business import get_trader
from zvt.api.technical import get_current_price
from zvt.charts.dcc_components import get_trader_detail_figures
from zvt.domain import TradingLevel
from zvt.reader.business_reader import AccountReader, OrderReader

trader = 'singlecointrader'
security = 'coin_binance_EOS/USDT'

trader_domain = get_trader(trader_name=trader, return_type='domain')[0]
account_reader = AccountReader(trader_names=['singlecointrader'], level=TradingLevel.LEVEL_1MIN)
order_reader = OrderReader(trader_names=['singlecointrader'])


def serve_layout():
    layout = html.Div(
        [
            daq.LEDDisplay(
                id='current_price',
                label="EOS/USDT current price",
                value=get_current_price(security_list=[security]),
                color="#FF5E5E"
            ),

            html.Div(id='trader-details', children=get_trader_detail_figures(trader_domain=trader_domain,
                                                                             account_reader=None,

def load_traders():
    global trader_domains
    global trader_names

    trader_domains = get_trader(return_type='domain')
    for trader in trader_domains:
        account_readers.append(AccountReader(trader_names=[trader.trader_name], level=trader.level))
        order_readers.append(OrderReader(trader_names=[trader.trader_name]))

    trader_names = [item.trader_name for item in trader_domains]