Help Text has important typo -- must pass $node_field by reference in custom function

The current #description text for the computed field input reads:
"Alternately, this code can be supplied by your own custom function named computed_field_field_next_increment_threshold_compute($node, $field, $node_field). Any code entered above will be ignored if the function is defined."

In my experience with this module, the $node_field parameter must be passed by reference, so the correct function pattern would be:
computed_field_field_next_increment_threshold_compute($node, $field, &$node_field).

This is an important distinction, as computed field will not work without the ampersand.