Kraken\Util\Buffer\BufferInterface::drain PHP Method

    public function drain();

 public function testApiDrain_EmptiesBuffer()
 {
     $result = $this->buffer->drain();
     $this->assertSame($this->initialString, $result);
     $this->assertSame('', (string) $this->buffer);
     $this->assertTrue($this->buffer->isEmpty());
 }