Model/getNeighbors: explictly state that initial indices have to be part of the set

        virtual std::pair<int, int> getPixelIndex(const ROOT::Math::XYZPoint& position) const;

        /**

         * @brief Return a set containing all channels neigboring the given one with a configurable maximum distance

         * @param idx       Index of the channel in question

         * @brief Return a set containing all pixels neighboring the given one with a configurable maximum distance

         * @param idx       Index of the pixel in question

         * @param distance  Distance for pixels to be considered neighbors

         * @return Set of neighboring pixel indices

         * @return Set of neighboring pixel indices, including the initial pixel

         *

         * @note The returned set should always also include the initial pixel indices the neighbors are calculated for

         */

        virtual std::set<Pixel::Index> getNeighbors(const Pixel::Index& idx, const size_t distance) const;

        /**

         * @brief Return a set containing all channels neigboring the two given channels with a configurable maximum distance

         * @param idx       Index of the first channel in question

         * @param last_idx  Index of the second channel in question

         * @brief Return a set containing all pixels neighboring the two given pixels with a configurable maximum distance

         * @param idx       Index of the first pixel in question

         * @param last_idx  Index of the second pixel in question

         * @param distance  Distance for pixels to be considered neighbors

         * @return Set of neighboring pixel indices

         * @return Set of neighboring pixel indices, including the two initial pixels

         *

         * @note The returned set should always also include the initial pixel indices the neighbors are calculated for

         */

        virtual std::set<Pixel::Index>

        getNeighbors(const Pixel::Index& idx, const Pixel::Index& last_idx, const size_t distance) const;