determineUsage = () => {
  importList.forEach((listValue, listKey) => {
    listValue.forEach((value, key) => {
      const exports = exportList.get(key);
      if (typeof exports !== 'undefined') {
        value.forEach((currentImport) => {
          let specifier;
          if (currentImport === IMPORT_NAMESPACE_SPECIFIER) {
            specifier = IMPORT_NAMESPACE_SPECIFIER;
          } else if (currentImport === IMPORT_DEFAULT_SPECIFIER) {
            specifier = IMPORT_DEFAULT_SPECIFIER;
          } else {
            specifier = currentImport;
          }
          if (typeof specifier !== 'undefined') {
            const exportStatement = exports.get(specifier);
            if (typeof exportStatement !== 'undefined') {
              const { whereUsed } = exportStatement;
              whereUsed.add(listKey);
              exports.set(specifier, { whereUsed });
            }
          }
        });
      }
    });
  });
}
traverse through all imports and add the respective path to the whereUsed-list
of the corresponding export