code: def set_xy_labels(units, kpc_per_arcsec, xlabelsize, ylabelsize, xyticksize):
      
      if units in 'arcsec' or kpc_per_arcsec is None:
  
          plt.xlabel('x (arcsec)', fontsize=xlabelsize)
          plt.ylabel('y (arcsec)', fontsize=ylabelsize)
  
      elif units in 'kpc':
  
          plt.xlabel('x (kpc)', fontsize=xlabelsize)
          plt.ylabel('y (kpc)', fontsize=ylabelsize)
  
      else:
          raise exc.PlottingException('The units supplied to the plotted are not a valid string (must be pixels | '
                                       'arcsec | kpc)')
  
      plt.tick_params(labelsize=xyticksize)
docs: Set the x and y labels of the figure, and set the fontsize of those labels.
  
      The x and y labels are always the distance scales, thus the labels are either arc-seconds or kpc and depend on the \
      units the figure is plotted in.
  
      Parameters
      -----------
      units : str
          The units of the y / x axis of the plots, in arc-seconds ('arcsec') or kiloparsecs ('kpc').
      kpc_per_arcsec : float
          The conversion factor between arc-seconds and kiloparsecs, required to plot the units in kpc.
      xlabelsize : int
          The fontsize of the x axes label.
      ylabelsize : int
          The fontsize of the y axes label.
      xyticksize : int
          The font size of the x and y ticks on the figure axes.