go Error方法优先级高于String方法

package main
 
import "fmt"
 
type Test string
 
func (t Test) String() string {
	return "test string"
}
 
func (t Test) Error() string {
	return "test error"
}
 
func main() {
	var t Test
	t = "a"
	fmt.Printf("%v\n", t)
}