def with_tenant(tenant,&blk)
      orig = self.current_tenant
      begin
        self.current_tenant = tenant
        return blk.call(tenant)
      ensure
        self.current_tenant = orig
      end
    end
def with_tenant(tenant,&blk)
      orig = self.current_tenant
      begin
        self.current_tenant = tenant
        return blk.call(tenant)
      ensure
        self.current_tenant = orig
      end
    end
Replace current_tenant with @tenant
 during the execution of @blk