Creating a new passwordless keystore and filling it with PEM certs (without private keys): documentation?

[Surowa]

I find the documentation for this library to be a bit lacking. Although there are some examples, I am missing my usecase (Creating a new passwordless keystore and filling it with PEM certs (without private keys)). There is no description or anything of the methods and functions that can be called. Anyone have an idea how to approach this?