public function join($strs = null)
{
return new self(s::join($this->value, XArray::unwrap($strs)));
}
public function testJoin()
{
$this->eq(s::join(array('a', 'b', 'c')), 'abc');
$this->eq(s::join(' ', array('a', 'b', 'c')), 'a b c');
}
public function join($str = '')
{
return new XString(s::join(XString::unwrap($str), $this->value));
}
