You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: pos.rs
    path of file: ./repos/namada/crates/tests/src/native_vp
    
    the code of the file until where you have to start completion: //! # PoS validity predicate tests
//!
//! The testing strategy is heavily relying on
//! [proptest state machine testing](https://github.com/AltSysrq/proptest/pull/257)
//! together with
//! [higher-order strategies](https://altsysrq.github.io/proptest-book/proptest/tutorial/higher-order.html).
//!
//! The system is being tested with arbitrary valid PoS parameters, arbitrary
//! valid initial state and:
//!
//! 1. One or more arbitrary valid transition. The happy path, these are very
//!    simple. We just test that they get accepted.
//! 1. One or more arbitrary valid transition, modified to make at least one of
//!    them invalid. Must be rejected.
//! 1. Arbitrary invalid storage modification. Must be rejected.
//!
//! The order of the arbitrary valid transitions is important as their storag
    
        fn init_state() -> BoxedStrategy<Self::State> {
            (arb_pos_params(None), 0..100_u64)
                .prop_flat_map(|(params, epoch)| {
                    // We're starting from an empty state
                    let state = vec![];
                    let epoch = Epoch(epoch);
                    let params = params.with_default_gov_params();
                    arb_valid_pos_action(&state).prop_map(move |valid_action| {
                        Self {
                            epoch,
                            params: params.clone(),
                            valid_actions: vec![],
                            invalid_pos_changes: vec![],
                            invalid_arbitrary_changes: vec![],
                            committed_valid_actions: vec![valid_action],
                        }
                    })
                })
                .boxed()
        }