code: public static @CheckForNull
      BugInstance findBugInstanceForMarker(IMarker marker) {
          BugCollectionAndInstance bci = findBugCollectionAndInstanceForMarker(marker);
          if (bci == null) {
              return null;
          }
          return bci.bugInstance;
      }
docs: Find the BugInstance associated with given FindBugs marker.
  
  @param marker
  a FindBugs marker
  @return the BugInstance associated with the marker, or null if we can't
  find the BugInstance