How to use the cairosvg.surface.cairo.Matrix function in CairoSVG

for transformation_type, transformation in transformations:
        values = [size(surface, value) for value in transformation.split(' ')]
        if transformation_type == 'matrix':
            matrix = cairo.Matrix(*values).multiply(matrix)
        elif transformation_type == 'rotate':
            angle = radians(float(values.pop(0)))
            x, y = values or (0, 0)
            matrix.translate(x, y)
            matrix.rotate(angle)
            matrix.translate(-x, -y)
        elif transformation_type == 'skewX':
            tangent = tan(radians(float(values[0])))
            matrix = cairo.Matrix(1, 0, tangent, 1, 0, 0).multiply(matrix)
        elif transformation_type == 'skewY':
            tangent = tan(radians(float(values[0])))
            matrix = cairo.Matrix(1, tangent, 0, 1, 0, 0).multiply(matrix)
        elif transformation_type == 'translate':
            if len(values) == 1:
                values += (0,)
            matrix.translate(*values)
        elif transformation_type == 'scale':
            if len(values) == 1:
                values = 2 * values
            matrix.scale(*values)

    try:
        matrix.invert()
    except cairo.Error:
        # Matrix not invertible, clip the surface to an empty path
        active_path = surface.context.copy_path()
        surface.context.new_path()
        surface.context.clip()

def transform(surface, string, gradient=None):
    """Transform ``surface`` or ``gradient`` if supplied using ``string``.

    See http://www.w3.org/TR/SVG/coords.html#TransformAttribute

    """
    if not string:
        return

    transformations = re.findall(r'(\w+) ?\( ?(.*?) ?\)', normalize(string))
    matrix = cairo.Matrix()
    for transformation_type, transformation in transformations:
        values = [size(surface, value) for value in transformation.split(' ')]
        if transformation_type == 'matrix':
            matrix = cairo.Matrix(*values).multiply(matrix)
        elif transformation_type == 'rotate':
            angle = radians(float(values.pop(0)))
            x, y = values or (0, 0)
            matrix.translate(x, y)
            matrix.rotate(angle)
            matrix.translate(-x, -y)
        elif transformation_type == 'skewX':
            tangent = tan(radians(float(values[0])))
            matrix = cairo.Matrix(1, 0, tangent, 1, 0, 0).multiply(matrix)
        elif transformation_type == 'skewY':
            tangent = tan(radians(float(values[0])))
            matrix = cairo.Matrix(1, tangent, 0, 1, 0, 0).multiply(matrix)

transformations = re.findall(r'(\w+) ?\( ?(.*?) ?\)', normalize(string))
    matrix = cairo.Matrix()
    for transformation_type, transformation in transformations:
        values = [size(surface, value) for value in transformation.split(' ')]
        if transformation_type == 'matrix':
            matrix = cairo.Matrix(*values).multiply(matrix)
        elif transformation_type == 'rotate':
            angle = radians(float(values.pop(0)))
            x, y = values or (0, 0)
            matrix.translate(x, y)
            matrix.rotate(angle)
            matrix.translate(-x, -y)
        elif transformation_type == 'skewX':
            tangent = tan(radians(float(values[0])))
            matrix = cairo.Matrix(1, 0, tangent, 1, 0, 0).multiply(matrix)
        elif transformation_type == 'skewY':
            tangent = tan(radians(float(values[0])))
            matrix = cairo.Matrix(1, tangent, 0, 1, 0, 0).multiply(matrix)
        elif transformation_type == 'translate':
            if len(values) == 1:
                values += (0,)
            matrix.translate(*values)
        elif transformation_type == 'scale':
            if len(values) == 1:
                values = 2 * values
            matrix.scale(*values)

    try:
        matrix.invert()
    except cairo.Error:
        # Matrix not invertible, clip the surface to an empty path

def transform(surface, string, gradient=None):
    """Transform ``surface`` or ``gradient`` if supplied using ``string``.

    See http://www.w3.org/TR/SVG/coords.html#TransformAttribute

    """
    if not string:
        return

    transformations = re.findall(r'(\w+) ?\( ?(.*?) ?\)', normalize(string))
    matrix = cairo.Matrix()
    for transformation_type, transformation in transformations:
        values = [size(surface, value) for value in transformation.split(' ')]
        if transformation_type == 'matrix':
            matrix = cairo.Matrix(*values).multiply(matrix)
        elif transformation_type == 'rotate':
            angle = radians(float(values.pop(0)))
            x, y = values or (0, 0)
            matrix.translate(x, y)
            matrix.rotate(angle)
            matrix.translate(-x, -y)
        elif transformation_type == 'skewX':
            tangent = tan(radians(float(values[0])))
            matrix = cairo.Matrix(1, 0, tangent, 1, 0, 0).multiply(matrix)
        elif transformation_type == 'skewY':
            tangent = tan(radians(float(values[0])))
            matrix = cairo.Matrix(1, tangent, 0, 1, 0, 0).multiply(matrix)
        elif transformation_type == 'translate':
            if len(values) == 1:
                values += (0,)
            matrix.translate(*values)

x2 = size(surface, gradient_node.get('x2', '100%'), width_ref)
        y1 = size(surface, gradient_node.get('y1', '0%'), height_ref)
        y2 = size(surface, gradient_node.get('y2', '0%'), height_ref)
        gradient_pattern = cairo.LinearGradient(x1, y1, x2, y2)

    elif gradient_node.tag == 'radialGradient':
        r = size(surface, gradient_node.get('r', '50%'), diagonal_ref)
        cx = size(surface, gradient_node.get('cx', '50%'), width_ref)
        cy = size(surface, gradient_node.get('cy', '50%'), height_ref)
        fx = size(surface, gradient_node.get('fx', str(cx)), width_ref)
        fy = size(surface, gradient_node.get('fy', str(cy)), height_ref)
        gradient_pattern = cairo.RadialGradient(fx, fy, 0, cx, cy, r)

    # Apply matrix to set coordinate system for gradient
    if gradient_node.get('gradientUnits') != 'userSpaceOnUse':
        gradient_pattern.set_matrix(cairo.Matrix(
            1 / width, 0, 0, 1 / height, - x / width, - y / height))

    # Apply transform of gradient
    transform(
        surface, gradient_node.get('gradientTransform'), gradient_pattern)

    # Apply gradient (

if 'viewBox' not in pattern_node:
            pattern_node['width'] = pattern_width
            pattern_node['height'] = pattern_height
            if pattern_node.get('patternContentUnits') == 'objectBoundingBox':
                pattern_node['transform'] = 'scale({}, {})'.format(
                    width, height)

    # Fail if pattern has an invalid size
    if pattern_width == 0.0 or pattern_height == 0.0:
        return False

    from .surface import SVGSurface  # circular import
    pattern_surface = SVGSurface(pattern_node, None, surface.dpi, surface)
    pattern_pattern = cairo.SurfacePattern(pattern_surface.cairo)
    pattern_pattern.set_extend(cairo.EXTEND_REPEAT)
    pattern_pattern.set_matrix(cairo.Matrix(
        pattern_surface.width / pattern_width, 0, 0,
        pattern_surface.height / pattern_height, -x, -y))
    surface.context.set_source(pattern_pattern)
    return True