Constructs an empty position-impact group.
The position effect wire string ("OPEN"/"CLOSE"), or undefined.
Sets the position effect from its wire string.
Throws ParamError when value is not "OPEN"/"CLOSE".
The position side wire string ("LONG"/"SHORT"), or undefined.
Sets the position side from its wire string.
Throws ParamError when value is not "LONG"/"SHORT".
Returns a fresh copy of this position-impact group.
Position-impact group: opening/closing effect and resulting side.