base.js
function encode (payload) {
    var checksum = checksumFn(payload)

    return base58.encode(Buffer.concat([
      payload,
      checksum
    ], payload.length + 4))
  }
function encode (payload) {
    var checksum = checksumFn(payload)

    return base58.encode(Buffer.concat([
      payload,
      checksum
    ], payload.length + 4))
  }
Encode a buffer as a base58-check encoded string