How not to output InformationKey when data is output to vtu

Support
1

I output data to .vtu with vtkXMLUnstructuredGridWriter.
However, VTU files always have
InformationKey name=“L2_NORM_RANGE” location=“vtkDataArray” length=“2”
Value index=“0”
0
Value
Value index=“1”
1.1661903912
Value
InformationKey
I don’t want to output InformationKey. How can I not output it?

from vtkmodules.vtkIOXML import vtkXMLDataSetWriter
from vtkmodules.vtkCommonCore import vtkPoints
import vtkmodules
from vtkmodules.vtkCommonCore import *
from vtkmodules.util import numpy_support
import numpy

if __name__ == '__main__':
    position = vtkPoints()
    position.SetDataType(VTK_FLOAT)
    position.InsertNextPoint(0, 0, 0)
    position.InsertNextPoint(1, 0, 0)
    position.InsertNextPoint(0, 1, 0)
    position.InsertNextPoint(0, 0, 1)
    position.InsertNextPoint(1, 0, .4)
    position.InsertNextPoint(0, 1, .6)

    grid = vtkmodules.vtkCommonDataModel.vtkUnstructuredGrid()
    grid.SetPoints(position)
    data = numpy.arange(0, 6, 1)
    data = numpy_support.numpy_to_vtk(data)
    data.SetName("pressure")
    grid.GetPointData().AddArray(data)

    writer = vtkmodules.vtkIOXML.vtkXMLUnstructuredGridWriter()
    #writer.SetDataModeToAppended()
    writer.SetDataMode(writer.Ascii)
    writer.SetFileName('a.vtu')
    writer.SetInputData(grid)
    writer.Write()