packages/workbox-webpack-plugin/src/lib/get-manifest-entries-from-compilation.js
function getKnownHashesFromAssets(assetMetadata) {
  const knownHashes = new Set();
  for (const metadata of Object.values(assetMetadata)) {
    knownHashes.add(metadata.hash);
  }
  return knownHashes;
}
function getKnownHashesFromAssets(assetMetadata) {
  const knownHashes = new Set();
  for (const metadata of Object.values(assetMetadata)) {
    knownHashes.add(metadata.hash);
  }
  return knownHashes;
}
function getKnownHashesFromAssets ( assetMetadata ) { const knownHashes = new Set ( ) ; for ( const metadata of Object . values ( assetMetadata ) ) { knownHashes . add ( metadata . hash ) ; } return knownHashes ; }
Given an assetMetadata mapping, returns a Set of all of the hashes that
are associated with at least one asset.

@param {Object<string, Object>} assetMetadata Mapping of asset paths to chunk
name and hash metadata.
@return {Set} The known hashes associated with an asset.

@private
Given an assetMetadata mapping returns a Set of all of the hashes that are associated with at least one asset .