Ideas:

• Set a minimum dimension for images.
• Find a way to detect dimensions before downloading the image.

What should be the result of new url("#")?
Browsers return different results.

In my understanding is that new url("#") should throw a validation error.

1. scheme start state
   1. [skip] If c is an ASCII alpha, append c, lowercased, to buffer, and set state to scheme state.
   2. [match] Otherwise, if state override is not given,