TypeCzech cannot see default parameters, as it runs before the actual function does,
but it can see how many parameters there are
in a function call. So the trick is to verify different signatures according to the
number of parameters. In the upper example to the left, a ['string', 'number'] is
checked for when there are two parameters. If there is only one parameter then it
must be a 'string'. Otherwise no type checks, which results in both defaults of
'Denzel Washington 66' being used. So defaults are assumed correct.
The lower example to the left, always expects the first parameter to be a 'string'.
The second parameter is ignored as an extra parameter.