Pub. Contract Code, § 21010

If the contractor fails to pay for any labor or material furnished for or in the doing of said work by any person, such person may within 90 days after the making of the final order hereinafter referred to, file with the county treasurer a verified statement of such facts, and such person may thereafter, within six months after the filing of such statement, bring an action on said bond in his or her own name, or if the person has assigned his or her claim, the action may be brought in the name of the assignee; provided, however, that the right of the county to recover on said bond shall be superior to the rights of any such person to recover thereon; provided, moreover, that if such statement shall be filed before the expiration of 20 days from the making of such final order, then the county treasurer shall be authorized to withhold from the contractor sufficient of the bonds, issued as herein provided, to satisfy said claim, and costs, which can reasonably be anticipated.