See associatedK3surface(SpecialCubicFourfold) and associatedK3surface(SpecialGushelMukaiFourfold).
The object associatedK3surface is a method function with options.
The source of this document is in /build/reproducible-path/macaulay2-1.25.05+ds/M2/Macaulay2/packages/SpecialFanoFourfolds.m2:3510:0.