add comment on why null check

maven3-interceptor/src/main/java/org/jvnet/hudson/maven3/listeners/HudsonMavenExecutionResult.java

@@ -54,7 +54,7 @@ public class HudsonMavenExecutionResult implements Serializable
                 MavenProjectInfo mavenProjectInfo = new MavenProjectInfo( mavenProject );
                 mavenProjectInfos.add( mavenProjectInfo );
                 BuildSummary buildSummary = mavenExecutionResult.getBuildSummary( mavenProject );
-                // NPE free :  weird this null ???
+                // NPE free : looks to have null here when the projects is not finished ie tests failures 
                 if ( buildSummary != null )
                 {
                   mavenProjectInfo.setBuildTime( buildSummary.getTime() );