How to use the tablib.packages.openpyxl.shared.xmltools.SubElement function in tablib

def _write_axis(self, plot_area, axis, label):

        ax = SubElement(plot_area, label)
        SubElement(ax, 'c:axId', {'val':str(axis.id)})

        scaling = SubElement(ax, 'c:scaling')
        SubElement(scaling, 'c:orientation', {'val':axis.orientation})
        if label == 'c:valAx':
            SubElement(scaling, 'c:max', {'val':str(axis.max)})
            SubElement(scaling, 'c:min', {'val':str(axis.min)})

        SubElement(ax, 'c:axPos', {'val':axis.position})
        if label == 'c:valAx':
            SubElement(ax, 'c:majorGridlines')
            SubElement(ax, 'c:numFmt', {'formatCode':"General", 'sourceLinked':'1'})
        SubElement(ax, 'c:tickLblPos', {'val':axis.tick_label_position})
        SubElement(ax, 'c:crossAx', {'val':str(axis.cross)})
        SubElement(ax, 'c:crosses', {'val':axis.crosses})
        if axis.auto:
            SubElement(ax, 'c:auto', {'val':'1'})
        if axis.label_align:
            SubElement(ax, 'c:lblAlgn', {'val':axis.label_align})
        if axis.label_offset:
            SubElement(ax, 'c:lblOffset', {'val':str(axis.label_offset)})
        if label == 'c:valAx':
            if self.chart.type == Chart.SCATTER_CHART:

def _write_chart(self, root):

        chart = self.chart

        ch = SubElement(root, 'c:chart')
        self._write_title(ch)
        plot_area = SubElement(ch, 'c:plotArea')
        layout = SubElement(plot_area, 'c:layout')
        mlayout = SubElement(layout, 'c:manualLayout')
        SubElement(mlayout, 'c:layoutTarget', {'val':'inner'})
        SubElement(mlayout, 'c:xMode', {'val':'edge'})
        SubElement(mlayout, 'c:yMode', {'val':'edge'})
        SubElement(mlayout, 'c:x', {'val':str(chart._get_margin_left())})
        SubElement(mlayout, 'c:y', {'val':str(chart._get_margin_top())})
        SubElement(mlayout, 'c:w', {'val':str(chart.width)})
        SubElement(mlayout, 'c:h', {'val':str(chart.height)})

        if chart.type == Chart.SCATTER_CHART:
            subchart = SubElement(plot_area, 'c:scatterChart')
            SubElement(subchart, 'c:scatterStyle', {'val':str('lineMarker')})
        else:
            if chart.type == Chart.BAR_CHART:
                subchart = SubElement(plot_area, 'c:barChart')
                SubElement(subchart, 'c:barDir', {'val':'col'})
            else:

ax = SubElement(plot_area, label)
        SubElement(ax, 'c:axId', {'val':str(axis.id)})

        scaling = SubElement(ax, 'c:scaling')
        SubElement(scaling, 'c:orientation', {'val':axis.orientation})
        if label == 'c:valAx':
            SubElement(scaling, 'c:max', {'val':str(axis.max)})
            SubElement(scaling, 'c:min', {'val':str(axis.min)})

        SubElement(ax, 'c:axPos', {'val':axis.position})
        if label == 'c:valAx':
            SubElement(ax, 'c:majorGridlines')
            SubElement(ax, 'c:numFmt', {'formatCode':"General", 'sourceLinked':'1'})
        SubElement(ax, 'c:tickLblPos', {'val':axis.tick_label_position})
        SubElement(ax, 'c:crossAx', {'val':str(axis.cross)})
        SubElement(ax, 'c:crosses', {'val':axis.crosses})
        if axis.auto:
            SubElement(ax, 'c:auto', {'val':'1'})
        if axis.label_align:
            SubElement(ax, 'c:lblAlgn', {'val':axis.label_align})
        if axis.label_offset:
            SubElement(ax, 'c:lblOffset', {'val':str(axis.label_offset)})
        if label == 'c:valAx':
            if self.chart.type == Chart.SCATTER_CHART:
                SubElement(ax, 'c:crossBetween', {'val':'midCat'})
            else:
                SubElement(ax, 'c:crossBetween', {'val':'between'})
            SubElement(ax, 'c:majorUnit', {'val':str(axis.unit)})

def _write_cell_style_xfs(self):
        cell_style_xfs = SubElement(self._root, 'cellStyleXfs', {'count':'1'})
        xf = SubElement(cell_style_xfs, 'xf',
            {'numFmtId':"0", 'fontId':"0", 'fillId':"0", 'borderId':"0"})

ax = SubElement(plot_area, label)
        SubElement(ax, 'c:axId', {'val':str(axis.id)})

        scaling = SubElement(ax, 'c:scaling')
        SubElement(scaling, 'c:orientation', {'val':axis.orientation})
        if label == 'c:valAx':
            SubElement(scaling, 'c:max', {'val':str(axis.max)})
            SubElement(scaling, 'c:min', {'val':str(axis.min)})

        SubElement(ax, 'c:axPos', {'val':axis.position})
        if label == 'c:valAx':
            SubElement(ax, 'c:majorGridlines')
            SubElement(ax, 'c:numFmt', {'formatCode':"General", 'sourceLinked':'1'})
        SubElement(ax, 'c:tickLblPos', {'val':axis.tick_label_position})
        SubElement(ax, 'c:crossAx', {'val':str(axis.cross)})
        SubElement(ax, 'c:crosses', {'val':axis.crosses})
        if axis.auto:
            SubElement(ax, 'c:auto', {'val':'1'})
        if axis.label_align:
            SubElement(ax, 'c:lblAlgn', {'val':axis.label_align})
        if axis.label_offset:
            SubElement(ax, 'c:lblOffset', {'val':str(axis.label_offset)})
        if label == 'c:valAx':
            if self.chart.type == Chart.SCATTER_CHART:
                SubElement(ax, 'c:crossBetween', {'val':'midCat'})
            else:
                SubElement(ax, 'c:crossBetween', {'val':'between'})
            SubElement(ax, 'c:majorUnit', {'val':str(axis.unit)})

def write(self):
        """ write a chart """

        root = Element('c:chartSpace',
            {'xmlns:c':"http://schemas.openxmlformats.org/drawingml/2006/chart",
             'xmlns:a':"http://schemas.openxmlformats.org/drawingml/2006/main",
             'xmlns:r':"http://schemas.openxmlformats.org/officeDocument/2006/relationships"})

        SubElement(root, 'c:lang', {'val':self.chart.lang})
        self._write_chart(root)
        self._write_print_settings(root)
        self._write_shapes(root)

        return get_document_content(root)

def _write_style(self, node):
        """ write style theme """

        style = SubElement(node, 'cdr:style')

        ln_ref = SubElement(style, 'a:lnRef', {'xmlns:a':self.schema, 'idx':'2'})
        scheme_clr = SubElement(ln_ref, 'a:schemeClr', {'val':'accent1'})
        SubElement(scheme_clr, 'a:shade', {'val':'50000'})

        fill_ref = SubElement(style, 'a:fillRef', {'xmlns:a':self.schema, 'idx':'1'})
        SubElement(fill_ref, 'a:schemeClr', {'val':'accent1'})

        effect_ref = SubElement(style, 'a:effectRef', {'xmlns:a':self.schema, 'idx':'0'})
        SubElement(effect_ref, 'a:schemeClr', {'val':'accent1'})

        font_ref = SubElement(style, 'a:fontRef', {'xmlns:a':self.schema, 'idx':'minor'})
        SubElement(font_ref, 'a:schemeClr', {'val':'lt1'})

def _write_borders(self):
        borders = SubElement(self._root, 'borders')

        # default
        border = SubElement(borders, 'border')
        SubElement(border, 'left')
        SubElement(border, 'right')
        SubElement(border, 'top')
        SubElement(border, 'bottom')
        SubElement(border, 'diagonal')

        # others
        table = {}
        index = 1
        for st in self._style_list:
            if hash(st.borders) != hash(style.DEFAULTS.borders) and hash(st.borders) not in table:
                table[hash(st.borders)] = str(index)
                border = SubElement(borders, 'border')
                # caution: respect this order
                for side in ('left','right','top','bottom','diagonal'):
                    obj = getattr(st.borders, side)
                    node = SubElement(border, side, {'style':obj.border_style})
                    SubElement(node, 'color', {'rgb':str(obj.color.index)})

def _write_series(self, subchart):

        for i, serie in enumerate(self.chart._series):
            ser = SubElement(subchart, 'c:ser')
            SubElement(ser, 'c:idx', {'val':str(i)})
            SubElement(ser, 'c:order', {'val':str(i)})

            if serie.legend:
                tx = SubElement(ser, 'c:tx')
                self._write_serial(tx, serie.legend)

            if serie.color:
                sppr = SubElement(ser, 'c:spPr')
                if self.chart.type == Chart.BAR_CHART:
                    # fill color
                    fillc = SubElement(sppr, 'a:solidFill')
                    SubElement(fillc, 'a:srgbClr', {'val':serie.color})
                # edge color
                ln = SubElement(sppr, 'a:ln')
                fill = SubElement(ln, 'a:solidFill')
                SubElement(fill, 'a:srgbClr', {'val':serie.color})

            if serie.error_bar:
                self._write_error_bar(ser, serie)

            marker = SubElement(ser, 'c:marker')
            SubElement(marker, 'c:symbol', {'val':serie.marker})

            if serie.labels:
                cat = SubElement(ser, 'c:cat')
                self._write_serial(cat, serie.labels)

def _write_style(self, node):
        """ write style theme """

        style = SubElement(node, 'cdr:style')

        ln_ref = SubElement(style, 'a:lnRef', {'xmlns:a':self.schema, 'idx':'2'})
        scheme_clr = SubElement(ln_ref, 'a:schemeClr', {'val':'accent1'})
        SubElement(scheme_clr, 'a:shade', {'val':'50000'})

        fill_ref = SubElement(style, 'a:fillRef', {'xmlns:a':self.schema, 'idx':'1'})
        SubElement(fill_ref, 'a:schemeClr', {'val':'accent1'})

        effect_ref = SubElement(style, 'a:effectRef', {'xmlns:a':self.schema, 'idx':'0'})
        SubElement(effect_ref, 'a:schemeClr', {'val':'accent1'})

        font_ref = SubElement(style, 'a:fontRef', {'xmlns:a':self.schema, 'idx':'minor'})
        SubElement(font_ref, 'a:schemeClr', {'val':'lt1'})