@Nullable
  public static QualifiedName findCanonicalImportPath(@NotNull PsiElement symbol, @Nullable PsiElement foothold) {
    return PyUtil.getNullableParameterizedCachedValue(symbol, Couple.of(symbol, foothold), QualifiedNameFinder::doFindCanonicalImportPath);
  }
@Nullable
  public static QualifiedName findCanonicalImportPath(@NotNull PsiElement symbol, @Nullable PsiElement foothold)