code: def gaugify(self, serie, squares, sq_dimensions, current_square):
      serie_node = self.svg.serie(serie)
      if self.half_pie:
          start_angle = 3 * pi / 2
          center = (
              (current_square[1] * sq_dimensions[0])
              - (sq_dimensions[0] / 2.0),
              (current_square[0] * sq_dimensions[1])
              - (sq_dimensions[1] / 4),
          )
          end_angle = pi / 2
      else:
          start_angle = 0
          center = (
              (current_square[1] * sq_dimensions[0])
              - (sq_dimensions[0] / 2.0),
              (current_square[0] * sq_dimensions[1])
              - (sq_dimensions[1] / 2.0),
          )
          end_angle = 2 * pi
  
      max_value = serie.metadata.get(0, {}).get("max_value", 100)
      radius = min([sq_dimensions[0] / 2, sq_dimensions[1] / 2]) * 0.9
      small_radius = radius * serie.inner_radius
  
      self.svg.gauge_background(
          serie_node,
          start_angle,
          center,
          radius,
          small_radius,
          end_angle,
          self.half_pie,
          self._serie_format(serie, max_value),
      )
  
      sum_ = 0
      for i, value in enumerate(serie.values):
          if value is None:
              continue
          ratio = min(value, max_value) / max_value
          if self.half_pie:
              angle = 2 * pi * ratio / 2
          else:
              angle = 2 * pi * ratio
  
          val = self._format(serie, i)
          metadata = serie.metadata.get(i)
  
          gauge_ = decorate(
              self.svg,
              self.svg.node(serie_node["plot"], class_="gauge"),
              metadata,
          )
  
          alter(
              self.svg.solid_gauge(
                  serie_node,
                  gauge_,
                  radius,
                  small_radius,
                  angle,
                  start_angle,
                  center,
                  val,
                  i,
                  metadata,
                  self.half_pie,
                  end_angle,
                  self._serie_format(serie, max_value),
              ),
              metadata,
          )
          start_angle += angle
          sum_ += value
  
      x, y = center
      self.svg.node(
          serie_node["text_overlay"],
          "text",
          class_="value gauge-sum",
          x=x,
          y=y + self.style.value_font_size / 3,
          attrib={"text-anchor": "middle"},
      ).text = self._serie_format(serie, sum_)
  
file_path: pygal/pygal/graph/solidgauge.py
imports: from math import pi, sqrt
  from pygal.graph.graph import Graph
  from pygal.util import alter, decorate
label_desc: Use image node_id 1 for calling the SolidGauge obj's underlying member method code with example usage: obj.gaugify(serie, squares, sq_dimensions, current_square) without return types