isOutputType function
Implementation
bool isOutputType(GraphQLType? type) =>
type != null &&
type.when(
enum_: (type) => true,
scalar: (type) => true,
object: (type) => true,
input: (type) => false,
union: (type) => true,
list: (type) => isOutputType(type.ofType),
nonNullable: (type) => isOutputType(type.ofType),
);