code: def loadACatalog(filename):
      
      ret = libxml2mod.xmlLoadACatalog(filename)
      if ret is None:raise treeError('xmlLoadACatalog() failed')
      return catalog(_obj=ret)
docs: Load the catalog and build the associated data structures.
        This can be either an XML Catalog or an SGML Catalog It
        will recurse in SGML CATALOG entries. On the other hand XML
         Catalogs are not handled recursively.