[vtk.js] vtkTubeFilter only creates tube for first line cell

If I manually create some poly data and pass it to the vtkTubeFilter, the output only shows a tube for the first cell (0th index).

I would expect the tube filter to produce a tube around every line cell much like the VTK-proper tube filter; is there something I am missing?

import vtk from 'vtk.js/Sources/vtk';
import vtkActor from 'vtk.js/Sources/Rendering/Core/Actor';
import vtkMapper from 'vtk.js/Sources/Rendering/Core/Mapper';
import vtkTubeFilter from 'vtk.js/Sources/Filters/General/TubeFilter';

const lines = vtk({
  vtkClass: 'vtkPolyData',
  points: {
    vtkClass: 'vtkPoints',
    dataType: 'Float32Array',
    numberOfComponents: 3,
    values: [
      0,0,0,
      1,1,0,
      1,1,1
    ]
  },
  lines: {
    vtkClass: 'vtkCellArray',
    dataType: 'Uint16Array',
    values: [
      2, 0, 2,
      2, 2, 1,
      2, 1, 0
    ]
  }
});

const tubeFilter = vtkTubeFilter.newInstance();
tubeFilter.setInputData(lines);
tubeFilter.setRadius(0.1);
const lineActor = vtkActor.newInstance();
const lineMapper = vtkMapper.newInstance();
lineActor.setMapper(lineMapper);
lineMapper.setInputConnection(tubeFilter.getOutputPort());

renderer.addActor(lineActor);

It is most likely a bug in JS that needs to be fixed.