PermissionObject.cs

//calls
Method1(webToPass);
Method2(listToPass);

//definition
private void Method1 (SPWeb web)
{
    web.permissions = "full";
}
Method2 Method2 (SPList list)
{
    list.permissions = "full";
}

//SHOULD BE

//calls
Method1 ((SPPermissionedObject)webToPass);
Method1 ((SPPermissionedObject)listToPass);

//functions
Method1 (SPPermissionedObject permissionedObject)
{
    permissionedObject.permissions = "full";
}