concatenate_datasets support axis=0 or 1 ？
That's not really difficult to add, though, no?
I think it can be done without copy.
Maybe let's add it to the roadmap?
I want to achieve the following result
![image](https://user-images.githubusercontent.com/12437751/99207426-f0c8db80-27f8-11eb-820a-4d9f7287b742.png)

concatenate_datasets support axis=0 or 1 ？ 
 I want to achieve the following result
![image](https://user-images.githubusercontent.com/12437751/99207426-f0c8db80-27f8-11eb-820a-4d9f7287b742.png)
 
 That's not really difficult to add, though, no?
I think it can be done without copy.
Maybe let's add it to the roadmap?