Technique mentioned in attached link, we calculate the degree of each node, Is there reason why we cannot just select the node with highest degree as the center? I think I'm missing something here. With assumption that I'm storing degree of each node say in a map along with reference to node.

https://github.com/williamfiset/Algorithms/blob/master/src/main/java/com/williamfiset/algorithms/graphtheory/treealgorithms/TreeCenter.java

Line 22-30 - degree of all the nodes are being stored in the array (degree[])