mod error {
    pub enum Error {}
}
use self::error::Error;
use petgraph::{
    Directed,
    graph::{
        Graph,
        NodeIndex,
    },
};
use std::result::Result as StdResult;
type Result<T> = StdResult<T, Error>;
type GraphType<'a> = Graph<&'a dyn Detector, (), Directed, usize>;

trait Detector {}

#[derive(Debug)]
struct MyGraph<'a>(GraphType<'a>);

fn main() -> Result<()> {
    Ok(())
}