protected function merge($x, $y, $z, $key)
    {
        // Convert the value into array.
        $ancestor = (strpos($x, PHP_EOL) !== false ? explode(PHP_EOL, $x) : array($x));
        $local = (strpos($y, PHP_EOL) !== false ? explode(PHP_EOL, $y) : array($y));
        $remote = (strpos($z, PHP_EOL) !== false ? explode(PHP_EOL, $z) : array($z));

        // Count number of lines in value or elements in new formed array.
        $count_ancestor = count($ancestor);
        $count_remote = count($remote);
        $count_local = count($local);

        // If number of lines is different in all 3 values.
        // For example : addition in remote and removal in local node.
        //
        // Else get the value of number of lines in updated node.
        // For example : Addition of 2 lines in local.
        // Suppose: $count_ancestor = 2 and $count_remote = 2
        // then, $count_local would be 4 now.
        if ($count_ancestor != $count_local
            && $count_local!= $count_remote
            && $count_ancestor != $count_remote
        ) {
            $merged = $this->linesAddedRemovedAndModified(
                $ancestor,
                $local,
                $remote,
                $count_ancestor,
                $count_local,
                $count_remote
            );
        } else {
            // Store the updated count value in a variable $count.
            if ($count_ancestor == $count_local) {
                $count = $count_remote;
            } else {
                $count = $count_local;
            }
            // If $count > $count_ancestor, that means lines have been added.
            // Otherwise, lines has been removed or modified.
            if ($count > $count_ancestor) {
                $merged = $this->linesAddedOrModified(
                    $ancestor,
                    $local,
                    $remote,
                    $count,
                    $count_remote,
                    $count_ancestor,
                    $count_local
                );
            } else {
                $merged = $this->linesRemovedOrModified(
                    $ancestor,
                    $local,
                    $remote,
                    $count_ancestor,
                    $count_local,
                    $count_remote
                );
            }
        }
        // Convert returned array back to string.
        $merged[$key] = implode(PHP_EOL, $merged);
        return $merged[$key];
    }