Make _normal2Camel recurse as well

_camel2Normal would take a hashref as an argument, but I needed
hash keys to be able to go the other way as well.

At least it got less readable which appears to be a goal of this set of subs

lib/Transmission/AttributeRole.pm

@@ -63,31 +63,38 @@ has eager_read => (
 );
 
 # this method name exists to prove a point - not to be readable...
-sub _camel2Normal {
+sub _convert {
     if(ref $_[1] eq 'HASH') {
         for my $camel (keys %{ $_[1] }) {
-            my $key = __PACKAGE__->_camel2Normal($camel);
+            my $key = $_[2]->($camel);
 
             if(ref $_[1]->{$camel} eq 'HASH') {
-                __PACKAGE__->_camel2Normal($_[1]->{$camel});
+                __PACKAGE__->_convert($_[1]->{$camel}, $_[2]);
             }
 
             $_[1]->{$key} = delete $_[1]->{$camel};
         }
     }
     else {
-        local $_ = $_[1];
+        return $_[2]->($_[1]);
+    }
+}
+
+sub _camel2Normal {
+    $_[0]->_convert( $_[1], sub {
+        local $_ = $_[0];
         tr/-/_/;
         s/([A-Z]+)/{ "_" .lc($1) }/ge;
         return $_;
-    }
+    } );
 }
-
 sub _normal2Camel {
-    local $_ = $_[1];
-    tr/_/-/;
-    s/_(\w)/{ uc($1) }/ge; # wild guess...
-    return $_;
+    $_[0]->_convert( $_[1], sub {
+        local $_ = $_[0];
+        tr/_/-/;
+        s/_(\w)/{ uc($1) }/ge; # wild guess...
+        return $_;
+    } );
 }
 
 =head1 LICENSE