Obtain ValueConverter's parameter in the fromView method



Is there any way to obtain the parameters of a ValueConverter in the fromView method?

I have a ValueConverter called RoNumber on an input:
<input value.bind="sum | roNumber:2" />

I can easily obtain the parameter(s) passed (number ‘2’ in this case) in the toView method : toView(value, parameter). However, the fromView method does not seem to be passed anything besides the value itself. Is this a bug or by design? Is there a way to obtain the parameters in the fromView method as well?