pub fn to_package_query(&self, direction: DependencyDirection) -> PackageQuery<'g> {
        self.graph
            .query_from_parts(iter::once(self.inner.package_ix).collect(), direction)
    }
Creates a `PackageQuery` consisting of this package, in the given direction.

The `PackageQuery` can be used to inspect dependencies in this graph.
guppy/src/graph/graph_impl.rs