public function testExists() { $this->assertTrue($this->seq->exists(function ($v) { return $v === 0; })); $a = $this->a; $this->assertTrue($this->seq->exists(function ($v) use($a) { return $v === $a; })); $this->assertFalse($this->seq->exists(function ($v) { return $v === 9999; })); $this->assertFalse($this->seq->exists(function ($v) { return $v === new \stdClass(); })); }