class_docstr: Dictionary holding analysis results.
  
  Conversion methods (e.g. to Pandas DataFrames) to be attached as necessary
  by each implementing method
docstr: Create bar chart of results
docstr_tok: ["Create","bar","chart","of","results"]
code: def plot(self, ax=None):
      """Create bar chart of results"""
      Si_df = self.to_df()
  
      if isinstance(Si_df, (list, tuple)):
          import matplotlib.pyplot as plt  # type: ignore
  
          if ax is None:
              fig, ax = plt.subplots(1, len(Si_df))
  
          for idx, f in enumerate(Si_df):
              barplot(f, ax=ax[idx])
  
          axes = ax
      else:
          axes = barplot(Si_df, ax=ax)
  
      return axes
  
imports: import pandas
  from SALib.plotting.bar import plot
label_desc: Use image node_id 3 for calling the ResultDict obj's underlying member method code with example usage: obj.plot(ax) and returns: axes