Sets or updates the billing account associated with a project. You specify the new billing account by setting the billing_account_name in the ProjectBillingInfo resource to the resource name of a billing account. Associating a project with an open billing account enables billing on the project and allows charges for resource usage. If the project already had a billing account, this method changes the billing account used for resource usage charges. Note: Incurred charges that have not yet been reported in the transaction history of the Google Cloud Console might be billed to the new billing account, even if the charge occurred before the new billing account was assigned to the project. The current authenticated user must have ownership privileges for both the project and the billing account. You can disable billing on the project by setting the billing_account_name field to empty. This action disassociates the current billing account from the project. Any billable activity of your in-use services will stop, and your application could stop functioning as expected. Any unbilled charges to date will be billed to the previously associated account. The current authenticated user must be either an owner of the project or an owner of the billing account for the project. Note that associating a project with a closed billing account will have much the same effect as disabling billing on the project: any paid resources used by the project will be shut down. Thus, unless you wish to disable billing, you should always call this method with the name of an open billing account.