BlackoilWellModel: move getMaxWellConnections to generic class

opm/simulators/wells/BlackoilWellModelGeneric.cpp

@@ -1369,4 +1369,28 @@ assignWellTracerRates(data::Wells& wsrpt,
     }
 }
 
+ std::vector<std::vector<int>>
+BlackoilWellModelGeneric::
+getMaxWellConnections() const
+{
+    std::vector<std::vector<int>> wells;
+
+    auto schedule_wells = schedule().getWellsatEnd();
+    schedule_wells.erase(std::remove_if(schedule_wells.begin(), schedule_wells.end(), not_on_process_), schedule_wells.end());
+    wells.reserve(schedule_wells.size());
+
+    // initialize the additional cell connections introduced by wells.
+    for ( const auto& well : schedule_wells )
+    {
+        std::vector<int> compressed_well_perforations = this->getCellsForConnections(well);
+
+        // also include wells with no perforations in case
+        std::sort(compressed_well_perforations.begin(),
+                  compressed_well_perforations.end());
+
+        wells.push_back(compressed_well_perforations);
+    }
+    return wells;
+}
+
 }