What is the theme of the poem presented to Wang Lun?

"To Wang Lun" is a farewell poem written by Li Bai, a famous poet in the Tang Dynasty, to Wang Lun, a local friend, when he was traveling in Jingxian (now southern Anhui). Theme is the content of poetry. Poetry is classified by content: 1, nostalgic poetry. 2. Poetry. 3. Landscape pastoral poetry. 4. War poems. 5. Travel poems and in my heart forever's poems. 6. Farewell poems. To Wang Lun is a farewell poem.