cannot combine splits merging and streaming?
Hi ! That's missing indeed. We'll try to implement this for the next version :)

I guess we just need to implement #2564 first, and then we should be able to add support for splits combinations
this does not work:
`dataset = datasets.load_dataset('mc4','iw',split='train+validation',streaming=True)`
with error:
`ValueError: Bad split: train+validation. Available splits: ['train', 'validation']`

these work:
`dataset = datasets.load_dataset('mc4','iw',split='train+validation')`
`dataset = datasets.load_dataset('mc4','iw',split='train',streaming=True)`
`dataset = datasets.load_dataset('mc4','iw',split='validation',streaming=True)`

i could not find a reference to this in the documentation and the error message is confusing. also would be nice to allow streaming for the merged splits
cannot combine splits merging and streaming? 
 this does not work:
`dataset = datasets.load_dataset('mc4','iw',split='train+validation',streaming=True)`
with error:
`ValueError: Bad split: train+validation. Available splits: ['train', 'validation']`

these work:
`dataset = datasets.load_dataset('mc4','iw',split='train+validation')`
`dataset = datasets.load_dataset('mc4','iw',split='train',streaming=True)`
`dataset = datasets.load_dataset('mc4','iw',split='validation',streaming=True)`

i could not find a reference to this in the documentation and the error message is confusing. also would be nice to allow streaming for the merged splits 
 Hi ! That's missing indeed. We'll try to implement this for the next version :)

I guess we just need to implement #2564 first, and then we should be able to add support for splits combinations