Yup, seeing method signatures like these is discouraging:

``` core::iter::Zip<core::iter::FilterMap<'_, (&std::collections::hash::set::HashSet<attr::Attribute>, &attr::Attribute), &attr::Attribute, core::iter::Zip<core::iter::Repeat<&std::collections::hash::set::HashSet<attr::Attribute>>, core::iter::Map<'_, (&attr::Attribute, &()), &attr::Attribute, std::collections::hash::map::Entries<'_, attr::Attribute, ()>>>>, core::iter::FilterMap<'_, (&std::collections::hash::set::HashSet<attr::Attribute>, &attr::Attribute), &attr::Attribute, core::iter::Zip<core::iter::Repeat<&std::collections::hash::set::HashSet<attr::Attribute>>, core::iter::Map<'_, (&attr::Attribute, &()), &attr::Attribute, std::collections::hash::map::Entries<'_, attr::Attribute, ()>>>>> ``