code: def project_interval_forward(self, c_interval):
          
          return self.dst_tm.g_to_c(self.src_tm.c_to_g(c_interval))
docs: project c_interval on the source transcript to the
          destination transcript
  
          :param c_interval: an :class:`hgvs.interval.Interval` object on the source transcript
          :returns: c_interval: an :class:`hgvs.interval.Interval` object on the destination transcript