matchers.go
func HavePrefix(prefix string, args ...interface{}) types.GomegaMatcher {
	return &matchers.HavePrefixMatcher{
		Prefix: prefix,
		Args:   args,
	}
}
func HavePrefix(prefix string, args ...interface{}) types.GomegaMatcher {
	return &matchers.HavePrefixMatcher{
		Prefix: prefix,
		Args:   args,
	}
}
//HavePrefix succeeds if actual is a string or stringer that contains the
//passed-in string as a prefix.  Optional arguments can be provided to construct
//via fmt.Sprintf().