pub fn mode(mut self, mode: SP1ProofMode) -> Self {
        self.mode = mode;
        self
    }
Set the proof mode to the given [`SP1ProofMode`].

# Details
This method is useful for setting the proof mode to a custom mode.

# Example
```rust,no_run
use sp1_sdk::{Prover, ProverClient, SP1ProofMode, SP1Stdin};

let elf = &[1, 2, 3];
let stdin = SP1Stdin::new();

let client = ProverClient::from_env();
let (pk, vk) = client.setup(elf);
let builder = client.prove(&pk, &stdin).mode(SP1ProofMode::Groth16).run();
```
crates/sdk/src/env/prove.rs