SystemField::loadCurrentFieldSet

static function loadCurrentFieldSet(string $operation): void
{
	if (self::$currentFieldSet === null)
	{
		self::$currentFieldSet = self::getDefaultFieldSet();
	}
	if (!array_key_exists($operation, self::$currentFieldSet))
	{
		return;
	}
	if (self::$currentFieldSet[$operation] === null)
	{
		self::$currentFieldSet[$operation] = [];

		$fieldList = self::getBuildedFieldList();
		if (!empty($fieldList))
		{
			foreach ($fieldList as $field)
			{
				if ($field::checkAllowedOperation($operation) && $field::isExists())
				{
					self::$currentFieldSet[$operation][] = $field;
				}
			}
			unset($field);
		}
		unset($fieldList);
	}
}