code: def pyang_plugin_init():
      
  
      # Register the plugin
      plugin.register_plugin(RESTCONFPlugin())
  
      # Register that we handle extensions from the YANG module 'ietf-restconf'
      grammar.register_extension_module(restconf_module_name)
  
      yd = (restconf_module_name, 'yang-data')
      statements.add_data_keyword(yd)
      statements.add_keyword_with_children(yd)
      statements.add_keywords_with_no_explicit_config(yd)
  
      # Register the special grammar
      for (stmt, occurance, (arg, rules), add_to_stmts) in restconf_stmts:
          grammar.add_stmt((restconf_module_name, stmt), (arg, rules))
          grammar.add_to_stmts_rules(add_to_stmts,
                                     [((restconf_module_name, stmt), occurance)])
  
      # Add validation functions
      statements.add_validation_fun('expand_2',
                                    [yd],
                                    v_yang_data)
  
      # Register special error codes
      error.add_error_code('RESTCONF_YANG_DATA_CHILD', 1,
                           "the 'yang-data' extension must have exactly one " +
                           "child that is a container")
docs: Called by pyang plugin framework at to initialize the plugin.