public AutoImportQuickFix addCandidates() {
    PsiFile existingImportFile = addCandidatesFromExistingImports();
    ProgressManager.checkCanceled(); // before expensive index searches
    addSymbolImportCandidates(existingImportFile);

    for (PyImportCandidateProvider provider : PyImportCandidateProvider.EP_NAME.getExtensionList()) {
      provider.addImportCandidates(myReference, myRefText, fix);
    }
    if (!fix.getCandidates().isEmpty()) {
      fix.sortCandidates();
      return fix;
    }
    return null;
  }
public AutoImportQuickFix addCandidates()