public function testContains() { $str = new MString('一二三四五'); $this->assertTrue($str->contains(new MString('四'))); $this->assertTrue($str->contains(new MString('一二'))); $this->assertTrue($str->contains(new MString('五'))); $this->assertTrue($str->contains(new MString('一二三四五'))); $this->assertFalse($str->contains(new MString('a'))); $this->assertFalse($str->contains(new MString('0'))); }