snafu$ for w in 'connect(' VariantMapper AssemblyMapper Normalizer Validator; do printf "%d $w\n" $(fgrep $w tests/*.py|wc -l); done

18 connect(
16 VariantMapper
15 AssemblyMapper
11 Normalizer
10 Validator

These are the minimum number of times we connect or instantiate these objects for tests. (The above excludes cases where we instantiate in loops, if any.)

Instead, use common fixtures that are created once per test session.