docs: def overplot_boundaries_from_params(ax, params, parmodel,
                                      list_islitlet,
                                      list_csu_bar_slit_center,
                                      micolors=('m', 'c'), linetype='--',
                                      labels=True, alpha_fill=None,
                                      global_offset_x_pix=0,
                                      global_offset_y_pix=0):
      """Overplot boundaries computed from fitted parameters.
  
      Parameters
      ----------
      ax : matplotlib axes
          Current plot axes.
      params : :class:`~lmfit.parameter.Parameters`
          Parameters to be employed in the prediction of the distorted
          boundaries.
      parmodel : str
          Model to be assumed. Allowed values are 'longslit' and
          'multislit'.
      list_islitlet : list of integers
          Slitlet numbers to be considered.
          longslits.
      list_csu_bar_slit_center : list of floats
          CSU bar slit centers of the considered slitlets.
      micolors : Python list
          List with two characters corresponding to alternating colors
          for odd and even slitlets.
      linetype : str
          Line type.
      labels : bool
          If True, display slilet label
      alpha_fill : float or None
          Alpha factor to be employed to fill slitlet region.
      global_integer_offset_x_pix : int or float
          Global offset in the X direction to be applied after computing
          the expected location.
      global_offset_y_pix : int or float
          Global offset in the Y direction to be applied after computing
          the expected location.
  
      Returns
      -------
      list_pol_lower_boundaries : python list
          List of numpy.polynomial.Polynomial instances with the lower
          polynomial boundaries computed for the requested slitlets.
      list_pol_upper_boundaries : python list
          List of numpy.polynomial.Polynomial instances with the upper
          polynomial boundaries computed for the requested slitlets.
  
  
      """
  
      # duplicate to shorten the variable names
      xoff = float(global_offset_x_pix)
      yoff = float(global_offset_y_pix)
  
      list_pol_lower_boundaries = []
      list_pol_upper_boundaries = []
      for islitlet, csu_bar_slit_center in \
              zip(list_islitlet, list_csu_bar_slit_center):
          tmpcolor = micolors[islitlet % 2]
          pol_lower_expected = expected_distorted_boundaries(
              islitlet, csu_bar_slit_center,
              [0], params, parmodel, numpts=101, deg=5, debugplot=0
          )[0].poly_funct
          list_pol_lower_boundaries.append(pol_lower_expected)
          pol_upper_expected = expected_distorted_boundaries(
              islitlet, csu_bar_slit_center,
              [1], params, parmodel, numpts=101, deg=5, debugplot=0
          )[0].poly_funct
          list_pol_upper_boundaries.append(pol_upper_expected)
          xdum = np.linspace(1, EMIR_NAXIS1, num=EMIR_NAXIS1)
          ydum1 = pol_lower_expected(xdum)
          ax.plot(xdum + xoff, ydum1 + yoff, tmpcolor + linetype)
          ydum2 = pol_upper_expected(xdum)
          ax.plot(xdum + xoff, ydum2 + yoff, tmpcolor + linetype)
          if alpha_fill is not None:
              ax.fill_between(xdum + xoff, ydum1 + yoff, ydum2 + yoff,
                              facecolor=tmpcolor, alpha=alpha_fill)
          if labels:
              # slitlet label
              yc_lower = pol_lower_expected(EMIR_NAXIS1 / 2 + 0.5)
              yc_upper = pol_upper_expected(EMIR_NAXIS1 / 2 + 0.5)
              xcsu = EMIR_NAXIS1 * csu_bar_slit_center / 341.5
              ax.text(xcsu + xoff, (yc_lower + yc_upper) / 2 + yoff,
                      str(islitlet),
                      fontsize=10, va='center', ha='center',
                      bbox=dict(boxstyle="round,pad=0.1", fc="white", ec="grey"),
                      color=tmpcolor, fontweight='bold',
                      backgroundcolor='white')
  
      # return lists with boundaries
      return list_pol_lower_boundaries, list_pol_upper_boundaries