in src/CodegenClass.hack [154:170]
protected function buildDeclaration(HackBuilder $builder): void {
$generics_dec = $this->buildGenericsDeclaration();
$builder->addWithSuggestedLineBreaksf(
'%s%s%s%s%s%s',
$this->declComment,
$this->isAbstract ? 'abstract ' : '',
$this->isFinal ? 'final ' : '',
$this->isXHP ? 'xhp ' : '',
'class '.$this->name.$generics_dec,
$this->extendsClass !== null
? HackBuilder::DELIMITER.'extends '.$this->extendsClass
: '',
);
$this->renderInterfaceList($builder, 'implements');
}