private static void addLanguageSpecificElements(Project project, int count, CompletionResultSet prefixed, FilePath filePath) {
    VirtualFile vFile = filePath.getVirtualFile();
    if (vFile == null) return;
    PsiFile psiFile = PsiManagerEx.getInstanceEx(project).findFile(vFile);
    if (psiFile == null) return;
    PlainTextSymbolCompletionContributor contributor = PlainTextSymbolCompletionContributorEP.forLanguage(psiFile.getLanguage());
    if (contributor == null) return;
    prefixed.addAllElements(contributor.getLookupElements(psiFile, count, prefixed.getPrefixMatcher().getPrefix()));
  }
private static void addLanguageSpecificElements(Project project, int count, CompletionResultSet prefixed, FilePath filePath)