@classmethod<EOL><INDENT>def _wal_name(cls):<DEDENT>
if cls._WAL_NAME is None:<EOL><INDENT>version = cls._dict_transform(psql_csv_run(<EOL>"<STR_LIT>"))<EOL>if int(version['<STR_LIT>']) >= <NUM_LIT>:<EOL><INDENT>cls._WAL_NAME = '<STR_LIT>'<EOL><DEDENT>else:<EOL><INDENT>cls._WAL_NAME = '<STR_LIT>'<EOL><DEDENT><DEDENT>return cls._WAL_NAME<EOL>
Sets and returns _WAL_NAME to 'wal' or 'xlog' depending on
version of postgres we are working with.

It is used for handling xlog -> wal rename in postgres v10