Can not parse --hash=sha256: ...

[hexagonrecursion]

import requirements
list(requirements.parse('cffi==1.14.3 --hash=sha256:22399ff4870fb4c7ef19fff6eeb20a8bbf15571913c181c78cb361024d574579'))

Throws an exception

InvalidRequirement: Parse error at "'--hash=s'": Expected stringEnd