code: def expected_parameters_from_cli(opts):
      
      expected = {}
      for x in opts.expected_parameters:
          x = x.split(':')
          if len(x) != 2:
              raise ValueError("option --expected-paramters not specified "
                               "correctly; see help")
          expected[x[0]] = float(x[1])
      return expected
docs: Parses the --expected-parameters arguments from the `plot_posterior`
      option group.
  
      Parameters
      ----------
      opts : ArgumentParser
          The parsed arguments from the command line.
  
      Returns
      -------
      dict
          Dictionary of parameter name -> expected value. Only parameters that
          were specified in the --expected-parameters option will be included; if
          no parameters were provided, will return an empty dictionary.