Incomplete work for refactoring regions and flows

lib/Slic3r/Config.pm

@@ -175,6 +175,22 @@ sub setenv {
     }
 }
 
+sub equals {
+    my ($self, $other) = @_;
+    return @{ $self->diff($other) } == 0;
+}
+
+sub diff {
+    my ($self, $other) = @_;
+    
+    my @diff = ();
+    foreach my $opt_key (sort @{$self->get_keys}) {
+        push @diff, $opt_key
+            if !$other->has($opt_key) || $other->serialize($opt_key) ne $self->serialize($opt_key);
+    }
+    return [@diff];
+}
+
 # this method is idempotent by design
 sub validate {
     my $self = shift;