public function buildPart($_from, $_to)
{
$this->sortCues();
$buffer = '';
if ($_from < 0 || $_from >= $this->getCuesCount()) {
$_from = 0;
}
if ($_to < 0 || $_to >= $this->getCuesCount()) {
$_to = $this->getCuesCount() - 1;
}
for ($j = $_from; $j <= $_to; $j++) {
/** @var SBVCue $cue */
$cue = $this->getCue($j);
$buffer .= $cue->getTimeCodeString() . $this->lineEnding;
$buffer .= $cue->getText() . $this->lineEnding;
$buffer .= $this->lineEnding;
}
$this->fileContent = $buffer;
return $this;
}