public function testStartsWith() { $str = new Str("Hello, world."); $this->assertTrue($str->startsWith("H")); $this->assertTrue($str->startsWith("Hello,")); $this->assertTrue($str->startsWith("HE", 0, true)); $this->assertTrue($str->startsWith("HE", null, true)); $this->assertFalse($str->startsWith(".")); $this->assertFalse($str->startsWith("world.")); $this->assertFalse($str->startsWith("LD.")); }