private static String findPrefixStatic(final PsiElement insertedElement, final int offsetInFile, ElementPattern<Character> prefixStartTrim) {
    if(insertedElement == null) return "";

    final Document document = insertedElement.getContainingFile().getViewProvider().getDocument();
    assert document != null;
    LOG.assertTrue(!PsiDocumentManager.getInstance(insertedElement.getProject()).isUncommited(document), "Uncommitted");

    final String prefix = CompletionUtil.findReferencePrefix(insertedElement, offsetInFile);
    if (prefix != null) return prefix;

    if (insertedElement.getTextRange().equals(insertedElement.getContainingFile().getTextRange()) || insertedElement instanceof PsiComment) {
      return CompletionUtil.findJavaIdentifierPrefix(insertedElement, offsetInFile);
    }

    return findPrefixDefault(insertedElement, offsetInFile, prefixStartTrim);
  }
private static String findPrefixStatic(final PsiElement insertedElement, final int offsetInFile, ElementPattern<Character> prefixStartTrim)