def _validate_field_names(self, *args: Any, **kwargs: Any) -> None:
        """Validate field names.

        Remove uniqueness constraint for field names from the original implementation.
        Required for having shorter ``Lag`` columns without specifying lag's type after ``LSN`` column already did so.
        """
        try:
            super(PatronictlPrettyTable, self)._validate_field_names(*args, **kwargs)
        except Exception as e:
            if 'Field names must be unique' not in str(e):
                raise e
Validate field names.

        Remove uniqueness constraint for field names from the original implementation.
        Required for having shorter ``Lag`` columns without specifying lag's type after ``LSN`` column already did so.
        
patroni/ctl.py