```"A scale expression.

Defined via [[Scalable.scale]]. Right-associative.

Examples:

2 ** vector
brakeFactor ** velocity

The scale operation is special because the receiver of the method invocation by which it is defined
is the [[right-hand side|rightOperand]], not the [[left-hand side|leftOperand]]. In other words,
`lhs ** rhs` corresponds to

rhs.scale(lhs)

while e. g. `lhs * rhs` corresponds to

lhs.times(rhs)

(the qualifier and argument swapped places)."
shared class ScaleOperation(factor, scalable)
extends BinaryOperation() {

"The factor by which the [[scalable]] is scaled"
shared MultiplyingExpression factor;
"The [[Scalable]] being scaled"
shared ScalingExpression scalable;

"The factor by which the [[scalable]] is scaled"
see (`value factor`)
shared actual MultiplyingExpression leftOperand = factor;
"The [[Scalable]] being scaled"
see (`value scalable`)
shared actual ScalingExpression rightOperand = scalable;

shared actual [MultiplyingExpression, ScalingExpression] children = [leftOperand, rightOperand];

operator = "**";

shared actual Result transform<out Result>(Transformer<Result> transformer)
=> transformer.transformScaleOperation(this);

shared actual void visit(Visitor visitor)
=> visitor.visitScaleOperation(this);

shared actual Boolean equals(Object that) {
if (is ScaleOperation that) {
return leftOperand==that.leftOperand && rightOperand==that.rightOperand;
} else {
return false;
}
}

shared actual Integer hash
=> 31 * (leftOperand.hash + 31*rightOperand.hash);

shared ScaleOperation copy(MultiplyingExpression leftOperand = this.leftOperand, ScalingExpression rightOperand = this.rightOperand) {
value ret = ScaleOperation(leftOperand, rightOperand);
copyExtraInfoTo(ret);
return ret;
}
}
```