Feature request: Query balances of multiple addresses at once

Hi, I want to query balance of multiple addresses.
There is an endpoint like;
`/api/address/3NfST3dLGP5bNEMsvjHB67nSmKhWjehwwy`
but this one takes only one address as a parameter. I want to query like
`/api/address/{address},{address},{address},...`
and blockcypher or insightbitpay has this feature like this link.
[Blockcypher](https://api.blockcypher.com/v1/btc/main/addrs/1As7UUdczmdQf48M36XYPfAQbxuqYDoL56;33aTFoHTSmvZAFNhQN3PfAdAdiFy7rpfnK)
[Insightbitpay](https://insight.bitpay.com/api/addrs/1As7UUdczmdQf48M36XYPfAQbxuqYDoL56,33aTFoHTSmvZAFNhQN3PfAdAdiFy7rpfnK/utxo)