Missing `optional_keys` option in Map schema

It is not possible to pass the optional_keys option to the Map schema. Map Interface it is cumbersome to use when defining larger Maps.

Map({
  "name": Str(),
  "date": Date(),
  "email": Str(), 

}, required_keys = ["name", "date"])

A much better option is to specify an optional_keys. It will save a lot of time

Map({
  "name": Str(),
  "date": Date(),
  "email": Str(), 

}, optional_keys = ["email"])