private static int SequenceNumber(MethodSymbol method)
{
// return a unique sequence number for the async implementation class that is independent of the compilation state.
int count = 0;
foreach (var m in method.ContainingNamespaceOrType().GetMembers(method.Name))
{
count++;
if (method == m) return count;
}
// It is possible we did not find any such members, e.g. for methods that result from the translation of
// async lambdas. In that case the method has already been uniquely named, so there is no need to
// produce a unique sequence number for the corresponding class, which already includes the (unique) method name.
return count;
}