code: def load(self, **kwargs):
          
  
          coordsys = kwargs.get('coordsys', 'CEL')
          extdir = kwargs.get('extdir', self.extdir)
          srcname = kwargs.get('srcname', None)
  
          self.clear()
          self.load_diffuse_srcs()
  
          for c in self.config['catalogs']:
  
              if isinstance(c, catalog.Catalog):
                  self.load_existing_catalog(c)
                  continue
  
              extname = os.path.splitext(c)[1]
              if extname != '.xml':
                  self.load_fits_catalog(c, extdir=extdir, coordsys=coordsys,
                                         srcname=srcname)
              elif extname == '.xml':
                  self.load_xml(c, extdir=extdir, coordsys=coordsys)
              else:
                  raise Exception('Unrecognized catalog file extension: %s' % c)
  
          for c in self.config['sources']:
  
              if 'name' not in c:
                  raise Exception(
                      'No name field in source dictionary:\n ' + str(c))
  
              self.create_source(c['name'], c, build_index=False)
  
          self._build_src_index()
docs: Load both point source and diffuse components.