VTK - remove a bunch of warnings (stricted checks where posible: we know that it is a string, int, boolean or null; checks on typeof 'undefined' can always be a string)
VTK - remove a bunch of warnings (stricted checks where posible: we know that it is a string, int, boolean or null; checks on typeof 'undefined' can always be a string)

vtkio/vtk,vtkio/vtk,vtkio/vtk,vtkio/vtk,vtkio/vtk,vtkio/vtk,vtkio/vtk,vtkio/vtk