Function load 

pub fn load(
    program: &Program,
    resolver: &mut dyn Resolver,
    snapshots: &mut Snapshots,
    limits: &InputLimits,
    cancel: Option<&AtomicBool>,
) -> Result<Inputs, RuntimeError>

Read every input of program, through resolver. Errors are about the input’s read(…) call, and say where in the data they are.