src/Role.php
public function setPermissionsAttribute(array $permissions)
    {
        if (!$this->id) {
            $this->save();
        }

        $this->revokeAll();

        collect($permissions)->map(function ($permission) {
            if (!in_array($permission, Policy::all())) {
                return;
            }

            $this->grant($permission);
        });
    }
public function setPermissionsAttribute(array $permissions)
    {
        if (!$this->id) {
            $this->save();
        }

        $this->revokeAll();

        collect($permissions)->map(function ($permission) {
            if (!in_array($permission, Policy::all())) {
                return;
            }

            $this->grant($permission);
        });
    }
Replace all existing permissions with a new set of permissions

@param array $permissions
@return void