What algorithm is used for Connectivity Filter

As the title says, I wish to know what algorithm the connectivity filter uses. Is there any way to find out or is it a custom Kitware algorithm?

If you look in the ParaView source at the proxy XML, you can connect the GUI name in ParaView to a C++ class name. Searching for “Connectivity”, I find this xml, which says the class used is vtkConnectivityFilter. Hope that helps!