[syjn99]

var DefaultSSZImports = map[string]string{
	"github.com/OffchainLabs/methodical-ssz/ssz": "ssz",
	"fmt":             "",
	"encoding/binary": "binary", // explicit alias kept only for golden-test stability
}

DefaultSSZImports asserts that encoding/binary is always used, but it's not true when there's no integer fields for SSZ objects. While working on SSZ Engine, newly defined SSZ objects don't have an integer field at all, making compile error when the files are generated using methodical.

Instead of pruning the unused one in downstream (which is Prysm), I'd rather submitted a change for methodical which is this PR. This PR prunes the entries of imports when they aren't referenced.

[syjn99]

@prestonvanloon

It would be nice if we can include this after #22 got merged.

[syjn99]

Force-pushed because the base branch (progression) is now included in main by #22. No content changes for this PR. Now merging it.