code: def set_account_metadata(self, metadata, clear=False, prefix=None,
              extra_info=None):
          
          return self._manager.set_account_metadata(metadata, clear=clear,
                  prefix=prefix)
docs: Accepts a dictionary of metadata key/value pairs and updates the
          account's metadata with them.
  
          If 'clear' is True, any existing metadata is deleted and only the
          passed metadata is retained. Otherwise, the values passed here update
          the account's metadata.
  
          By default, the standard account metadata prefix ('X-Account-Meta-') is
          prepended to the header name if it isn't present. For non-standard
          headers, you must include a non-None prefix, such as an empty string.
  
          The 'extra_info' parameter is included for backwards compatibility. It
          is no longer used at all, and will not be modified with swiftclient
          info, since swiftclient is not used any more.