Alphanumeric 生成随机字母数字.

AlphanumericOrSymbol 生成随机字母数字或符号.

ClarityCaptcha 生成明确的验证码（排除容易混淆的字符串）.

IntRange returns, as an int, a non-negative pseudo-random number in the range interval [min,max].

IntRangeZeroFill Returns a string of random numbers,if less than the specified length, preceded by zeros.

LowerCase 生成随机小写字符串.

NewUUID create uuid.

Numeric 生成随机数字字符串.

Random 随机生成字符串.

UpperCase 生成随机大写字符串.