How to use the cairosvg.helpers.transform function in CairoSVG

old_parent_node = self.parent_node
        old_font_size = self.font_size
        old_context_size = self.context_width, self.context_height
        self.parent_node = node

        if "font" in node:
            font = parse_font(node["font"])
            for att in font:
                if att not in node:
                    node[att] = font[att]

        self.font_size = size(self, node.get('font-size', '12pt'))
        self.context.save()

        # Apply transformations
        transform(self, node.get('transform'))

        # Find and prepare opacity, masks and filters
        mask = parse_url(node.get('mask')).fragment
        filter_ = parse_url(node.get('filter')).fragment
        opacity = float(node.get('opacity', 1))

        if filter_:
            prepare_filter(self, node, filter_)

        if filter_ or mask or (opacity < 1 and node.children):
            self.context.push_group()

        # Move to (node.x, node.y)
        self.context.move_to(
            size(self, node.get('x'), 'x'),
            size(self, node.get('y'), 'y'))

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 (

def draw_pattern(surface, node, name):
    """Draw a pattern image."""
    pattern_node = surface.patterns[name]
    pattern_node.tag = 'g'
    transform(surface, pattern_node.get('patternTransform'))

    if pattern_node.get('viewBox'):
        if not (size(surface, pattern_node.get('width', 1), 1) and
                size(surface, pattern_node.get('height', 1), 1)):
            return False
    else:
        if not (size(surface, pattern_node.get('width', 0), 1) and
                size(surface, pattern_node.get('height', 0), 1)):
            return False

    if pattern_node.get('patternUnits') == 'userSpaceOnUse':
        x = size(surface, pattern_node.get('x'), 'x')
        y = size(surface, pattern_node.get('y'), 'y')
        pattern_width = size(surface, pattern_node.get('width', 0), 1)
        pattern_height = size(surface, pattern_node.get('height', 0), 1)
    else: