package mainimport s "strings"import "fmt" var echo = fmt.Printlnfunc main() {    echo("Contains:  ", s.Contains("test", "es"))    echo("Count:     ", s.Count("test", "t"))    echo("HasPrefix: ", s.HasPrefix("test", "te"))    echo("HasSuffix: ", s.HasSuffix("test", "st"))    echo("Index:     ", s.Index("test", "e"))    echo("Join:      ", s.Join([]string{"a", "b"}, "-"))    echo("Repeat:    ", s.Repeat("a", 5))    echo("Replace:   ", s.Replace("foo", "o", "0", -1))    echo("Replace:   ", s.Replace("foo", "o", "0", 1))    echo("Split:     ", s.Split("a-b-c-d-e", "-"))    echo("ToLower:   ", s.ToLower("TEST"))    echo("ToUpper:   ", s.ToUpper("test"))	echo("Len: ", len("hello"))    echo("Char:", "hello"[1])}