Input Types of NON_NULL Shown as Nullable Types when Input has a Default Value

[DimuthuMadushan]

Description:
Consider following service:

service /graphql on new graphql:Listener(9000) {
  resource function get greeting(string name = "Walter") returns string {
      return "Hello, " + name;
  }
}

In the schema, argument name is shown as nullable type argument. But it should be a NON_NULL type.