* @description Groups the PR's files' by owner based on the CODEOWNERs file.
 * @param {string[]} files - the gitStream's files context variable
 * @param {Object} pr - the gitStream's pr context variable
 * @param {string} token - access token with repo:read scope, used to read the CODEOWNERS file
 * @param {string} pathToCodeOwners - path from repo root to CODEOWNERS file
 * @returns {Map} - Map from owner name to list of files they own

            // > An asterisk "*" matches anything except a slash.
            // 2.
            // > Other consecutive asterisks are considered regular asterisks
            // > and will match according to the previous rules.
            const unescaped = p2.replace(/\\\*/g, '[^\\/]*')
            return p1 + unescaped
        }
    ],

    [
        // unescape, revert step 3 except for back slash