return this->
what is that mean in C++

..

```
using namespace std;

IOM ConfigurationManager::getIOM(int iomId) {
  return this->IOMs[iomId];

```

..

the relevant part of the whole code is above.

The code that I wrote is from a huge project which was waiting for someone to finish. I am not good at C++ but I need to learn more not to lose that job. Anyway, the project is full of "return this->...." which I thought unnecessary, that's why I asked is there smt special that we should use that notation