android.util.Patterns.EMAIL在单元测试期间返回null

我有一个代码,在验证器中有 android.util.Patterns.EMAIL_ADDRESS.它在对设备运行时运行正常,但是当我在单元测试中运行此代码时,它返回null.
此外,我尝试复制和粘贴模式中的内部代码,如下例所示.

validateEmail1有效// whyyy ???

validateEmail2返回null

private static final Pattern EMAIL = Pattern.compile(
        "[a-zA-Z0-9+._%-+]{1,256}" +
                "@" +
                "[a-zA-Z0-9][a-zA-Z0-9-]{0,64}" +
                "(" +
                "." +
                "[a-zA-Z0-9][a-zA-Z0-9-]{0,25}" +
                ")+"
);

public boolean validateEmail1(String email) {
    return EMAIL.matcher(email).matches();
}

public boolean validateEmail2(String email) {
    return Patterns.EMAIL_ADDRESS.matcher(email).matches();
}