Function parse_srcset 

pub fn parse_srcset(input: &str) -> Vec<ImageCandidate>

Parse a srcset attribute value into its image candidates.

Invalid candidates are skipped (the reference implementation logs them and continues); a fully invalid or empty input yields an empty list.

use parse_srcset::parse_srcset;
assert_eq!(parse_srcset("img.png").len(), 1);
assert!(parse_srcset("img.png 1w 2x").is_empty()); // mixed descriptors