public static String[] split(final String str, final char separator) {
        return split(str, separator, false);
    }
Splits the provided text into an array, separator specified.

A null input String returns null.

Strings.split(null, *)         = null
Strings.split("", *)           = []
Strings.split("a.b.c", '.')    = ["a", "b", "c"]
Strings.split("a..b.c", '.')   = ["a", "b", "c"]
Strings.split("a:b:c", '.')    = ["a:b:c"]
Strings.split("a b c", ' ')    = ["a", "b", "c"]
jraft-rheakv/rheakv-core/src/main/java/com/alipay/sofa/jraft/rhea/util/Strings.java