Return a new parameter object to a cell in the global dynamic environment
created by calling converter on init. If converter is
not specified, it defaults to identity.
— Scheme Macro: parameterize bindings [body...]
Dynamically bind parameter objects specified in bindings
and evaluate body. Each binding in bindings has the
form (expr1 expr2), where expr1 evaluates to a parameter
object. The order of evaluation for expr1 and expr2 is
not specified.