code: def load(self, _from):
          
  
          def load_rec(inode, config):
              """Recursive part of loading."""
              for k in config:
                  if isinstance(config[k], dict) and \
                     k not in ['value', 'default']:
                      if k in inode:
                          load_rec(inode[k], config[k])
                      else:
                          LOG.debug("+ config element: '%s'", k)
                  else:
                      inode[k] = config[k]
  
          with open(_from, 'r') as infile:
              obj = yaml.load(infile, Loader=ConfigLoader)
              upgrade(obj)
              load_rec(self.node, obj)
              self['config_file'] = os.path.abspath(_from)
docs: Load the configuration dictionary from file.