anchor.diff:  `True` when passed on the command line without any modifier and `False` when the `--no-` modifier is prefixed.
   For example:
   
  -`command --verbose`
  +`program --verbose`
   
   and:
   
  -`command --no-verbose`, or `command --noverbose`
  +`program --no-verbose`, or `program --noverbose`
   
   In `go-getoptions` this is accomplished with:
   
  
positive.code: 
  === Enforce Single Dash Mode
  
  Set by defining `opt.SetMode("singleDash")`.
  
  |===
  |Given option |Interpretation
  
negative.code: Parse an option string argument into a Floating point value and provide an user error if the string provided is not a valid floating point.
  For example:
  
  `program --approximation 3.5`
  
  and:
  
  ----
  $ program --approximation string
  
  Error: 'string' is not a valid floating point value.
  ----
  