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: pathfinding.rs
    path of file: ./repos/veloren/world/src
    
    the code of the file until where you have to start completion: use crate::sim::WorldSim;
use common::path::Path;
//use hashbrown::hash_map::DefaultHashBuilder;
use vek::*;

#[allow(dead_code)]
pub struct SearchCfg {
    // 0.0 = no discount, 1.0 = free travel
    path_discount: f32,
    // Cost per metre altitude change per metre horizontal
    // 0.0 = n
    
    pub fn search(self, _a: Vec2<i32>, _b: Vec2<i32>) -> Option<Path<i32>> {
        // TODO: implement this function

        //let heuristic = |pos: &Vec2<i32>| (pos - b).map(|e| e as f32).magnitude();
        // Astar::new(
        //     100_000,
        //     a,
        //     heuristc,
        //     DefaultHashBuilder::default(),
        // );

        None
    }