src/Model/Admin.php
public function setAdminData($key, $value, $userId = null)
    {
        return $this->setUnsetAdminData($key, $value, $userId, true);
    }
public function setAdminData($key, $value, $userId = null)
    {
        return $this->setUnsetAdminData($key, $value, $userId, true);
    }
Sets a piece of admin data

@param  string $key    The key to set
@param  mixed  $value  The value to set
@param  mixed  $userId The user's ID, if null active user is used.

@return boolean