pub trait Visitor<'a, S: SchemaDefinition> {
// Provided methods
fn visit_input_object_type_definition(
&mut self,
_input_object_type_definition: &'a S::InputObjectTypeDefinition,
) { ... }
fn visit_enum_type_definition(
&mut self,
_enum_type_definition: &'a S::EnumTypeDefinition,
) { ... }
}