docstr: :return:
docstr_tok: [":","return",":"]
code: def _init_data(self):
      """
  
      :return:
      """
      if self._df.empty:
          raise ValueError("df is empty.")
  
      self.data = self._get_data()
  
imports: import math
  import importlib
  from typing import Iterable
  import pandas
  import plotly.offline
  import plotly.graph_objs
  from plotly.subplots import make_subplots
  from plotly.figure_factory import create_distplot
label_desc: Use image node_id 2 for calling the BaseGraph obj's underlying member method code with example usage: obj._init_data() without return types