No way to add custom headers to UrbanAirshipClient about java-library

[martin-vct]

Hi @zhe-zhao,

We have well noted your request about accepting custom headers. We'll check internally if this could be added in future updates.

In the meantime, I wanted to let you know we still have a way to setup the Client with Proxy:
https://docs.airship.com/api/libraries/java/#configuration

Realm realm = new Realm.Builder("user", "password")
    .setScheme(Realm.AuthScheme.BASIC)
    .build();

ProxyServer proxyServer = new ProxyServer.Builder("test.urbanairship.com", 8080)
    .setRealm(realm)
    .build();

AsyncRequestClient asyncRequestClient = AsyncRequestClient.newBuilder()
    .setProxyServer(proxyServer)
    .build();

UrbanAirshipClient client = UrbanAirshipClient.newBuilder()
    .setKey("key")
    .setSecret("secret")
    .setClient(asyncRequestClient)
    .build();