unicode.isSpace
IsSpace reports whether the rune is a space character as defined by Unicode’s White Space property; in the Latin-1 space this is
IsSpace报告符文是否是Unicode的白色空间属性所定义的空间字符；在Latin-1空间中，这就是 '\t', '\n', '\v', '\f', '\r', ' ', U+0085 (NEL), U+00A0 (NBSP).