Moved Tractography::__WriterBase__::verify_stream() from public to protected access
Moved Tractography::__WriterBase__::verify_stream() from public to protected access

MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3