## Why is this an issue?

There are several reasons to use a group in a regular expression:

- to change the precedence (e.g. `do(g|or)` will match 'dog' and 'door')
- to remember parenthesised part of the match in the case of capturing group
- to improve readability

In any case, having an empty group is most probably a mistake. Either it is a leftover after refactoring and should be removed, or the actual parentheses were intended and were not escaped.

### Noncompliant code example

    "foo()"  // Noncompliant, will match only 'foo'

### Compliant solution

    "foo\\(\\)"  // Matches 'foo()'