wifi: Add another function to test if a PSDU map contains a Trigger Frame

src/wifi/model/he/he-frame-exchange-manager.cc

@@ -54,6 +54,14 @@ IsTrigger(const WifiPsduMap& psduMap)
            psduMap.cbegin()->second->GetHeader(0).IsTrigger();
 }
 
+bool
+IsTrigger(const WifiConstPsduMap& psduMap)
+{
+    return psduMap.size() == 1 && psduMap.cbegin()->first == SU_STA_ID &&
+           psduMap.cbegin()->second->GetNMpdus() == 1 &&
+           psduMap.cbegin()->second->GetHeader(0).IsTrigger();
+}
+
 TypeId
 HeFrameExchangeManager::GetTypeId()
 {

src/wifi/model/he/he-frame-exchange-manager.h

@@ -51,6 +51,13 @@ typedef std::unordered_map<uint16_t /* staId */, Ptr<const WifiPsdu> /* PSDU */>
  */
 bool IsTrigger(const WifiPsduMap& psduMap);
 
+/**
+ * \param psduMap a PSDU map
+ * \return true if the given PSDU map contains a single PSDU including a single MPDU
+ *         that carries a Trigger Frame
+ */
+bool IsTrigger(const WifiConstPsduMap& psduMap);
+
 /**
  * \ingroup wifi
  *