private function prepareBuilder() { if ($this->value !== null) { $this->value->append($this->delimiter); } else { $this->value = (new StringBuilder())->append($this->prefix); } return $this->value; }
public function testSetCharAt() { $sb = new StringBuilder(); $sb->append('This'); $sb->setCharAt(2, 'u'); $this->assertEquals('Thus', (string) $sb); }