docs: def _update_slits(self, hdr):
          """Recreate slits"""
  
          # Slits.
          # For the moment we will fuse only reference slits
  
          # clean existing slits
          self.slits = {}
          mm = []
          for idx in self.LBARS:
  
              # References from header
              try:
                  slit_t = hdr["SLIFL%d" % idx]
                  target_type = TargetType(slit_t)
              except KeyError:
                  target_type = TargetType.UNKNOWN
  
              xref = hdr.get("XRSLI%d" % idx, -100) - 1
              yref = hdr.get("YRSLI%d" % idx, -100) - 1
              target_coordinates = (xref, yref)
  
              xref = hdr.get("XVSLI%d" % idx, -100) - 1
              yref = hdr.get("YVSLI%d" % idx, -100) - 1
              target_coordinates_v = (xref, yref)
  
              mm.append((idx, target_type, target_coordinates, target_coordinates_v))
  
          bag = merge_slits(mm, max_slits=3, tol=1e-2)
  
          for idx, l_ids in bag.items():
              r_ids = [lid + EMIR_NBARS for lid in l_ids]
  
              lbars = {lid: self.bars[lid] for lid in l_ids}
              rbars = {rid: self.bars[rid] for rid in r_ids}
  
              this = LogicalSlit(idx, lbars=lbars, rbars=rbars)
              # References from header
              ref = mm[l_ids[0] - 1]
              this.target_type = ref[1]
              this.target_coordinates = ref[2]
              this.target_coordinates_v = ref[3]
              self.slits[idx] = this