// For example, a type might implement a Scan method that
// has nothing to do with fmt.Scanner, but we still want to check
// the methods that are intended to implement fmt.Scanner.
-// To do that, the arguments that have a + prefix are treated as
+// To do that, the arguments that have a = prefix are treated as
// signals that the canonical meaning is intended: if a Scan
// method doesn't have a fmt.ScanState as its first argument,
// we let it go. But if it does have a fmt.ScanState, then the