In CbmEvent class, add match presence to ToString + add explicit Clear method

core/data/CbmEvent.cxx

@@ -60,7 +60,9 @@ std::string CbmEvent::ToString() const
    std::stringstream ss;
    ss << "Event " << fNumber << " at t = " << fTimeStart
   		<< " ns. Registered data types: " << fIndexMap.size()
-  		<< ", data objects: " << fNofData << "\n";
+  		<< ", data objects: " << fNofData
+                << ( nullptr != fMatch ? ", with matches" : ", without matches" )
+                << "\n";
    for (auto it = fIndexMap.begin(); it != fIndexMap.end(); it++) {
   	 ss << "          -- Data type " << it->first
   			<< ", number of data " << it->second.size() << "\n";

core/data/CbmEvent.h

@@ -18,7 +18,7 @@
 
 #include "CbmDefs.h"         // for ECbmDataType, ECbmModuleId::kStsTrack
 #include "CbmMatch.h"        // for CbmMatch
-#include "CbmVertex.h"       // for CbmVertex
+#include "CbmVertex.h"       // for CbmVertex, found in core/data/global
 
 /** @class CbmEvent
  ** @brief Class characterising one event by a collection of links (indices)
@@ -51,6 +51,9 @@ class CbmEvent: public TObject {
 			if ( fMatch ) delete fMatch;
 		}
 
+                /** Overload TObject Clear to clear the map! **/
+                void Clear( Option_t * /*option*/ ) { fIndexMap.clear(); }
+
 
 		/** Add a data object to the index map
 		 ** @param DataType  Type of data (for values see CbmDetectorList.h)

core/data/test/_GTestCbmEvent.cxx

@@ -265,7 +265,7 @@ TEST(_GTestCbmEvent, CheckSettersAndGetters)
      compareEventMap(test, 9,  3, ECbmDataType::kStsTrack,   ststrack);
    }
 
-   EXPECT_STREQ("Event -111 at t = 1 ns. Registered data types: 6, data objects: 9\n          -- Data type 0, number of data 2\n          -- Data type 200, number of data 1\n          -- Data type 201, number of data 1\n          -- Data type 202, number of data 1\n          -- Data type 203, number of data 1\n          -- Data type 204, number of data 3\n", test.ToString().c_str());
+   EXPECT_STREQ("Event -111 at t = 1 ns. Registered data types: 6, data objects: 9, without matches\n          -- Data type 0, number of data 2\n          -- Data type 200, number of data 1\n          -- Data type 201, number of data 1\n          -- Data type 202, number of data 1\n          -- Data type 203, number of data 1\n          -- Data type 204, number of data 3\n", test.ToString().c_str());
 
  }