tidy: address repeated branch issue

alib2graph_data/src/graph/mixed/MixedGraph.hpp

@@ -172,11 +172,12 @@ void MixedGraph<TNode, TEdge>::addNode(Params &&... params) {
 template<typename TNode, typename TEdge>
 bool MixedGraph<TNode, TEdge>::addEdge(const TEdge &e) {
   auto search_succ = m_succ_list.find(e.first);
-  auto search_pred = m_pred_list.find(e.first);
-
   if (search_succ != m_succ_list.end() && search_succ->second.find(e.second) != search_succ->second.end()) {
     return false;
-  } else if (search_pred != m_pred_list.end() && search_pred->second.find(e.second) != search_pred->second.end()) {
+  }
+
+  auto search_pred = m_pred_list.find(e.first);
+  if (search_pred != m_pred_list.end() && search_pred->second.find(e.second) != search_pred->second.end()) {
     return false;
   }
@@ -197,11 +198,12 @@ bool MixedGraph<TNode, TEdge>::addEdge(const TEdge &e) {
 template<typename TNode, typename TEdge>
 bool MixedGraph<TNode, TEdge>::addEdge(TEdge &&e) {
   auto search_succ = m_succ_list.find(e.first);
-  auto search_pred = m_pred_list.find(e.first);
-
   if (search_succ != m_succ_list.end() && search_succ->second.find(e.second) != search_succ->second.end()) {
     return false;
-  } else if (search_pred != m_pred_list.end() && search_pred->second.find(e.second) != search_pred->second.end()) {
+  }
+
+  auto search_pred = m_pred_list.find(e.first);
+  if (search_pred != m_pred_list.end() && search_pred->second.find(e.second) != search_pred->second.end()) {
     return false;
   }