framework/web/User.php
public function getIdentity($autoRenew = true)
    {
        if ($this->_identity === false) {
            if ($this->enableSession && $autoRenew) {
                try {
                    $this->_identity = null;
                    $this->renewAuthStatus();
                } catch (\Exception $e) {
                    $this->_identity = false;
                    throw $e;
                } catch (\Throwable $e) {
                    $this->_identity = false;
                    throw $e;
                }
            } else {
                return null;
            }
        }

        return $this->_identity;
    }
public function getIdentity($autoRenew = true)
    {
        if ($this->_identity === false) {
            if ($this->enableSession && $autoRenew) {
                try {
                    $this->_identity = null;
                    $this->renewAuthStatus();
                } catch (\Exception $e) {
                    $this->_identity = false;
                    throw $e;
                } catch (\Throwable $e) {
                    $this->_identity = false;
                    throw $e;
                }
            } else {
                return null;
            }
        }

        return $this->_identity;
    }
Returns the identity object associated with the currently logged-in user.
When [[enableSession]] is true, this method may attempt to read the user's authentication data
stored in session and reconstruct the corresponding identity object, if it has not done so before.
@param bool $autoRenew whether to automatically renew authentication status if it has not been done so before.
This is only useful when [[enableSession]] is true.
@return IdentityInterface|null the identity object associated with the currently logged-in user.
`null` is returned if the user is not logged in (not authenticated).
@see login()
@see logout()