docs: OSMTurnRelation createTurnRelation(ReaderRelation relation) {
          OSMTurnRelation.Type type = OSMTurnRelation.Type.getRestrictionType(relation.getTag("restriction"));
          if (type != OSMTurnRelation.Type.UNSUPPORTED) {
              long fromWayID = -1;
              long viaNodeID = -1;
              long toWayID = -1;
  
              for (ReaderRelation.Member member : relation.getMembers()) {
                  if (ReaderElement.WAY == member.getType()) {
                      if ("from".equals(member.getRole())) {
                          fromWayID = member.getRef();
                      } else if ("to".equals(member.getRole())) {
                          toWayID = member.getRef();
                      }
                  } else if (ReaderElement.NODE == member.getType() && "via".equals(member.getRole())) {
                      viaNodeID = member.getRef();
                  }
              }
              if (fromWayID >= 0 && toWayID >= 0 && viaNodeID >= 0) {
                  return new OSMTurnRelation(fromWayID, viaNodeID, toWayID, type);
              }
          }
          return null;
      }