in src/HackBuilder.hack [473:485]
public function addInlineComment(?string $comment): this {
if ($comment === null) {
return $this;
}
// Max length of each line of the docblock. Subtract 3 to compensate
// for the initial "// "
$max_length = $this->getMaxCodeLength() - 3;
$lines = $this->splitString($comment, $max_length);
foreach ($lines as $line) {
$this->addLine(\rtrim('// '.$line));
}
return $this;
}