You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: exchange_client.rs
    path of file: ./repos/mmb/exchanges/binance/src
    
    the code of the file until where you have to start completion: use super::binance::Binance;
use crate::support::BinanceOrderInfo;
use anyhow::{anyhow, Context, Result};
use async_trait::async_trait;
use function_name::named;
use itertools::Itertools;
use mmb_core::exchanges::general::exchange::RequestResult;
use mmb_core::exchanges::general::order::cancel::CancelOrderResult;
use mmb_core::exchanges::general::order::create::CreateOrderResult;
use mmb_core::exchanges::general::order::get_order_trades::OrderTrade;
use mmb_core::exchanges::general::request_type::RequestType;
use mmb_core::exchanges::rest_client::UriBuilder;
use mmb_core::exchanges::traits::{ExchangeClient, ExchangeError, Support};
use mmb_domain::events::{EventSourceType, ExchangeBalancesAndPositions};
use mmb_domain::exchanges::symbol::Symbol;
use mmb_domain::market::CurrencyPair;
use mmb_domain::order::pool::OrderRef;
use mmb_domain::order::snapshot::Price;
use mmb_domain::order::snapshot::*;
use mmb_domain::position::{ActivePosit
    
    async fn get_balance_and_positions(&self) -> Result<ExchangeBalancesAndPositions> {
        // Binance does return positions from GET request /fapi/v2/account but without liquidation_price field
        // so we have to use separate requests for balance and positions
        Ok(match self.settings.is_margin_trading {
            true => {
                let (balance_response, position_response) =
                    tokio::join!(self.request_get_balance(), self.request_get_position());
                ExchangeBalancesAndPositions {
                    balances: self.parse_derivative_balance(&balance_response?)?,
                    positions: Some(
                        self.get_active_positions(&position_response?)?
                            .map(|position| Ok::<_, anyhow::Error>(position?.derivative))
                            .try_collect()?,
                    ),
                }
            }
            false => {
                let balance_response = self.request_get_balance().await?;
                ExchangeBalancesAndPositions {
                    balances: self.parse_spot_balance(&balance_response)?,
                    positions: None,
                }
            }
        })
    }