code: def _prepare_render(self):
      for c in self:
          if not hasattr(c, "_is_tab_chart"):
              setattr(c, "_is_tab_chart", True)
          if hasattr(c, "dump_options"):
              c.json_contents = c.dump_options()
          if hasattr(c, "theme"):
              if c.theme not in ThemeType.BUILTIN_THEMES:
                  self.js_dependencies.add(c.theme)
  
file_path: pyecharts/pyecharts/charts/composite_charts/tab.py
imports: import uuid
  from jinja2 import Environment
  from ...None import types
  from ...commons import utils
  from ...globals import CurrentConfig, ThemeType
  from ...options.charts_options import TabChartGlobalOpts
  from ...render import engine
  from ..mixins import CompositeMixin
label_desc: Use image node_id 4 for calling the Tab obj's underlying member method code with example usage: obj._prepare_render() without return types