pub trait Source: FlowComponent<Input = ()> {
    // Required method
    fn stream(
        &self,
    ) -> FlowFuture<'_, SourceOutput<Self::Output, Self::Error>, Self::Error>;
}pub trait Source: FlowComponent<Input = ()> {
    // Required method
    fn stream(
        &self,
    ) -> FlowFuture<'_, SourceOutput<Self::Output, Self::Error>, Self::Error>;
}