code: def write_config(config, filename=None):
      
      if not filename:
          filename = CONFIG_DEFAULT_PATH
  
      with open(filename, 'w') as f:
          json.dump(config, f, indent=4)
docs: Write the provided configuration to a specific location.
  
      Args:
          config (dict): a dictionary with the configuration to load.
          filename (str): the name of the file that will store the new configuration. Defaults to ``None``.
              If ``None``, the HOME of the current user and the string ``.bigchaindb`` will be used.