certificate stream for TLS missed after first communication

When do TLS communication, we need to load certificate, there are two ways to load certificate

1. set certificate file path
2. set certificate stream

due to security purpose, we ussually load certificate from stream with #2, the problem is: the stream will lost after first communication, that means need to set the stream before each call, can we keep the certificate stream in memory?

Class: SslConfig and related methods are:

setClientKeyCertChainPathStream
setClientPrivateKeyPathStream
setClientTrustCertCollectionPathStream
setServerKeyCertChainPathStream
setServerPrivateKeyPathStream
setServerTrustCertCollectionPathStream

### Environment

* Dubbo version: 2.7.6,2.7.7,2.7.8
* Operating System version: macOS Catalina 10.15.6
* Java version: 1.8