WIP: Resolve "std::set and std::map instead of std::list in wolf nodes"

Closes #213 (closed)

include/core/capture/capture_base.h

@@ -176,8 +176,8 @@ inline unsigned int CaptureBase::id() const
 
 inline FrameBasePtr CaptureBase::getFrame() const
 {
-    frame_ptr_.expired();
-    return frame_ptr_.lock();
+    if(frame_ptr_.expired()) return nullptr;
+    else return frame_ptr_.lock();
 }
 
 inline void CaptureBase::setFrame(const FrameBasePtr _frm_ptr)