code: func (t *typeResolver) IsNullable(schema *spec.Schema) bool {
  	nullable := t.isNullable(schema)
  	return nullable || len(schema.AllOf) > 0
  }
docs: // IsNullable hints the generator as to render the type with a pointer or not.
  //
  // A schema is deemed nullable (i.e. rendered by a pointer) when:
  // - a custom extension says it has to be so
  // - it is an object with properties
  // - it is a composed object (allOf)
  //
  // The interpretation of Required as a mean to make a type nullable is carried on elsewhere.