pub struct FooStruct<'a> {
  pub bars: Vec<&'a str>,
}

pub trait FooTrait<'a> {
  fn getBars(&self) -> &'a Vec<&'a str>;
}

impl<'a> FooTrait<'a> for FooStruct<'a> {
  fn getBars(&self) -> &'a Vec<&'a str> {
    &self.bars // cannot infer an appropriate lifetime for borrow expression due to conflicting requirements
  }
}