errors

var (
	ErrInvalidSpecification = errors.New("specification must be a struct pointer")
	ErrNotAStruct           = errors.New("cannot wrap a non-struct type")
	ErrNotExported          = errors.New("field is not exported")
	ErrNotSettable          = errors.New("field is not settable")
	ErrMissingRequiredField = errors.New("required field is zero valued")
)