How to use the pykml.factory.KML_ElementMaker.href function in pykml

# colobar location
    if loc.split()[0] == 'lower':
        oy, sy = '0', '0'
    elif loc.split()[0] == 'upper':
        oy, sy = '1', '1'
    if loc.split()[1] == 'left':
        ox, sx = '0', '0'
    elif loc.split()[1] == 'right':
        ox, sx = '1', '1'

    # generate KML screen overlay object
    cbar_overlay = KML.ScreenOverlay(
        KML.name('colorbar'),
        KML.Icon(
            KML.href("{}".format(os.path.basename(cbar_file))),
            KML.viewBoundScale(0.75)
        ),
        KML.overlayXY(x=ox, y=oy, xunits="fraction", yunits="fraction"),
        KML.screenXY(x=sx, y=sy, xunits="fraction", yunits="fraction"),
        KML.size(x="0", y="250", xunits="pixel", yunits="pixel"),
        KML.rotation(0),
        KML.visibility(1),
        KML.open(0)
    )
    #print('add colorbar.')
    return cbar_overlay

def writeKML(file, img, colorbarImg,inps):
  South, North, West, East = get_lat_lon(file)  
  ############## Generate kml file
  print ('generating kml file')
  doc = KML.kml(KML.Folder(KML.name(os.path.basename(file))))
  slc = KML.GroundOverlay(KML.name(os.path.basename(img)),KML.Icon(KML.href(os.path.basename(img))),\
                          KML.TimeSpan(KML.begin(),KML.end()),\
                          KML.LatLonBox(KML.north(str(North)),KML.south(str(South)),\
                                        KML.east(str(East)),  KML.west(str(West))))
  doc.Folder.append(slc)

  #############################
  print ('adding colorscale')
  latdel = North-South
  londel = East-West
  
  slc1   = KML.ScreenOverlay(KML.name('colorbar'),KML.Icon(KML.href(os.path.basename(colorbarImg))),
        KML.overlayXY(x="0.0",y="1",xunits="fraction",yunits="fraction",),
        KML.screenXY(x="0.0",y="1",xunits="fraction",yunits="fraction",),
        KML.rotationXY(x="0.",y="1.",xunits="fraction",yunits="fraction",),
        KML.size(x="0",y="0.3",xunits="fraction",yunits="fraction",),
      )

cb_img = "images"
            cb_dir = os.path.join(fig_dir,cb_img)
            shutil.rmtree(cb_dir,True)
            os.mkdir(cb_dir)
            cb_filename = "colorbarfig%s.png" % figno
            try:
                plotfigure.kml_colorbar(cb_filename)
                shutil.move(cb_filename,cb_dir)
            except:
                print("KML ===> Warning : Something went wrong when creating colorbar")

            # add link to KML file, even if colorbar didn't get created.
            cb_str = os.path.join(cb_img,cb_filename)
            colorbar = KML.ScreenOverlay(
                KML.name("Colorbar"),
                KML.Icon(KML.href(cb_str)),
                KML.overlayXY(x="0.025", y="0.05", xunits="fraction", yunits="fraction"),
                KML.screenXY(x="0.025", y="0.05",xunits="fraction", yunits="fraction"))

            doc_fig.Document.append(colorbar)
            # -----  Done with colorbar ------

        # ------------------ done with fig/doc.kml file ------------------
        fig_file = open(os.path.join(fig_dir,"doc.kml"),'wt')
        fig_file.write('\n')

        # In case we used CDATA in any snippets or descriptions.  For some reason
        #  get converted to >tags<, which balloons don't translate.
        kml_text = etree.tostring(etree.ElementTree(doc_fig),pretty_print=True).decode()
        kml_text = kml_text.replace('>','>')
        kml_text = kml_text.replace('<','<')
        fig_file.write(kml_text)

KML.latitude(location['loc'].latitude),
              KML.longitude(location['loc'].longitude),
              KML.altitude(location['loc'].altitude),
            ),
            KML.Orientation(
              KML.heading(location['loc'].heading),
              KML.tilt(-location['loc'].tilt),
              KML.roll(location['loc'].roll),
            ),
            KML.Scale(
              KML.x(10),
              KML.y(10),
              KML.z(-10),
            ),
            KML.Link(
              KML.href('models/three_unit_lines.dae'),
            )
        )
    )
    return pm

def kml_overlay(self):
        url = urlparse.urljoin( options.baseurl, '/'.join( str(t) for t in (self.level, self.col, self.row) ) + "."+self.filetype )

        goverlay = KML.GroundOverlay()
        goverlay.Region = self.kml_region()
        goverlay.drawOrder = KML.drawOrder(self.level * DEFAULT_DRAW_ORDER_FACTOR)
        goverlay.Icon = KML.Icon(KML.href(url))
        goverlay.LatLonBox = self.latlonbox()


        assert_valid(goverlay)
        return goverlay

out_name_base = os.path.splitext(out_file)[0]
    data_png_file = out_name_base + '.png'
    print('writing {} with dpi={}'.format(data_png_file, inps.fig_dpi))
    plt.savefig(data_png_file, pad_inches=0.0,
                transparent=True, dpi=inps.fig_dpi)    

    # 2.3 Generate KML file
    proj_name = metadata.get('PROJECT_NAME', 'InSAR_MintPy')
    doc = KML.kml(KML.Folder(KML.name(proj_name)))

    # Add data png file
    img_name = os.path.splitext(os.path.basename(data_png_file))[0]
    img = KML.GroundOverlay(
        KML.name(img_name),
        KML.Icon(
            KML.href(os.path.basename(data_png_file))
        ),
        KML.altitudeMode('clampToGround'),
        KML.LatLonBox(KML.north(str(north)),
                      KML.east(str(east)),
                      KML.south(str(south)),
                      KML.west(str(west)))
    )
    doc.Folder.append(img)

    # Add colorbar png file
    cbar_file = '{}_cbar.png'.format(out_name_base)
    cbar_overlay = generate_cbar_element(cbar_file,
                                         vmin=inps.vlim[0],
                                         vmax=inps.vlim[1],
                                         unit=inps.disp_unit,
                                         cmap=inps.colormap,

def write_kml(list_of_networks):
            has_data = False

            doc = KML.Document(
                KML.name("PH5 Events"),
                KML.Style(
                    KML.IconStyle(
                        KML.color('FF1400FF'),
                        KML.scale('1.25'),
                        KML.Icon(
                            KML.href(
                                'http://maps.google.com/mapfiles/' +
                                'kml/shapes/open-diamond.png')
                        )
                    ),
                    id='star'
                ),
            )

            for network in list_of_networks:
                network_folder = KML.Folder(KML.name(
                    "Network Code: " + str(network.code) +
                    " reportnum: " + network.reportnum))
                for shot_line in network.shot_lines:
                    folder = KML.Folder(
                        KML.name("ShotLine " + str(shot_line.name[-3:])))
                    for shot in shot_line.shots: