PromisePay declares public key but doesn't use it

[Invertisment]

I'm trying to figure out the API and I've found an unused public key:

android-sdk/promisepay/src/main/java/com/github/promisepay/PromisePay.java

Line 57 in 6b96c51

this.publicKey = publicKey;

I'd suggest to remove the publicKey parameter as it creates a false assumption of security. Also it creates a publicKey dependency in the app and then it's not used.
Probably it still requires a full-featured library at the backend (assuming this is an Android front-end library).