How to use the svgutils.transform.TextElement function in svgutils

def _gen_grid(self, dx, dy, width=0.5):
        xmax, ymax = 1000, 1000
        x, y = 0, 0
        lines = []
        txt = []
        while x < xmax:
            lines.append(_transform.LineElement([(x, 0), (x, ymax)],
                                                width=width))
            txt.append(_transform.TextElement(x, dy/2, str(x), size=self.size))
            x += dx
        while y < ymax:
            lines.append(_transform.LineElement([(0, y), (xmax, y)],
                                                width=width))
            txt.append(_transform.TextElement(0, y, str(y), size=self.size))
            y += dy
        return lines+txt

import sys 

#create new SVG figure
fig = sg.SVGFigure("16cm", "6.5cm")

# load matpotlib-generated figures
fig1 = sg.fromfile('sigmoid_fit.svg')
fig2 = sg.fromfile('anscombe.svg')

# get the plot objects
plot1 = fig1.getroot()
plot2 = fig2.getroot()
plot2.moveto(280, 0, scale=0.5)

# add text labels
txt1 = sg.TextElement(25,20, "A", size=12, weight="bold")
txt2 = sg.TextElement(305,20, "B", size=12, weight="bold")

# append plots and labels to figure
fig.append([plot1, plot2])
fig.append([txt1, txt2])

# save generated SVG files
fig.save("fig_final.svg")

#create new SVG figure
fig = sg.SVGFigure("16cm", "6.5cm")

# load matpotlib-generated figures
fig1 = sg.fromfile('sigmoid_fit.svg')
fig2 = sg.fromfile('anscombe.svg')

# get the plot objects
plot1 = fig1.getroot()
plot2 = fig2.getroot()
plot2.moveto(280, 0, scale=0.5)

# add text labels
txt1 = sg.TextElement(25,20, "A", size=12, weight="bold")
txt2 = sg.TextElement(305,20, "B", size=12, weight="bold")

# append plots and labels to figure
fig.append([plot1, plot2])
fig.append([txt1, txt2])

# save generated SVG files
fig.save("fig_final.svg")

def _gen_grid(self, dx, dy, width=0.5):
        xmax, ymax = 1000, 1000
        x, y = 0, 0
        lines = []
        txt = []
        while x < xmax:
            lines.append(_transform.LineElement([(x, 0), (x, ymax)],
                                                width=width))
            txt.append(_transform.TextElement(x, dy/2, str(x), size=self.size))
            x += dx
        while y < ymax:
            lines.append(_transform.LineElement([(0, y), (xmax, y)],
                                                width=width))
            txt.append(_transform.TextElement(0, y, str(y), size=self.size))
            y += dy
        return lines+txt

def __init__(self, text, x=None, y=None, **kwargs):
        params = {'size': CONFIG['text.size'],
                  'weight': CONFIG['text.weight'],
                  'font': CONFIG['text.font']}
        if x is None or y is None:
            x, y = CONFIG['text.position']
        params.update(kwargs)
        element = _transform.TextElement(x, y, text, **params)
        Element.__init__(self, element.root)