code: def overlap(self, chart: Base):
      self.options.get("legend")[0].get("data").extend(
          chart.options.get("legend")[0].get("data")
      )
      if self.options.get("legend")[0].get("selected") is not None:
          self.options.get("legend")[0].get("selected").update(
              chart.options.get("legend")[0].get("selected")
          )
      self.options.get("series").extend(chart.options.get("series"))
      # to merge colors of chart
      for c in chart.colors[: len(chart.colors) - self.default_color_n]:
          self.colors.insert(len(self.colors) - self.default_color_n, c)
      return self
  
imports: from ..None import options
  from ..None import types
  from ..charts.base import Base
  from ..globals import RenderType, ThemeType, ToolTipFormatterType
  from ..types import Optional, Sequence
label_desc: Use image node_id 5 for calling the RectChart obj's underlying member method code with example usage: obj.overlap(chart) and returns: self