diff --git a/jay_diff.py b/jay_diff.py
index c8cd26d..66421a8 100644
--- a/jay_diff.py
+++ b/jay_diff.py
@@ -1,29 +1,33 @@
 from copy import deepcopy
 
-def jay_diff_rev(data, temp_data):
-	new_data = {}
+
+def jay_diff_rev(delta, data, temp_data):
 	for k in data.keys():
 		if k not in temp_data:
 			temp_data[k] = data[k]
-			new_data[k] = data[k]
+			delta[k] = data[k]
+		else:
 			if isinstance(temp_data[k], dict):
-				new_data, temp_data = jay_diff_rev(data[k], temp_data[k])
-	return new_data, temp_data
+				if k not in delta:
+					delta[k] = {}
+				jay_diff_rev(delta[k], data[k], temp_data[k])
 
 
-def jay_diff_plus(data, temp_data):
-	temp = deepcopy(temp_data)
-	res, _ = jay_diff_rev(data, temp)
-	return res
+def jay_diff_plus(_old, _new):
+	__old = deepcopy(_old)
+	delta = {}
+	jay_diff_rev(delta, _new, __old)
+	return delta
 
 
-def jay_diff_minus(data, temp_data):
-	temp = deepcopy(data)
-	res, _ = jay_diff_rev(temp_data, temp)
-	return res
+def jay_diff_minus(_old, _new):
+	__new = deepcopy(_new)
+	delta = {}
+	jay_diff_rev(delta, _old, __new)
+	return delta
 
 
-def jay_diff_upd(data, temp_data):
+def jay_diff_upd(temp_data, data):
 	new_data = {}
 	for k in data.keys():
 		if k in temp_data:
@@ -72,85 +76,76 @@ def jay_merge_minus(d, u):
 
 if __name__ == '__main__':
 
-	a = {'a':'hamburger', 'b':'fries', 'c':'coke'}
-	b = {'a':'hamburger', 'b':'fries', 'c':'pepsi'}
-	c = {'a':'hamburger', 'b':'fries', 'c':'pepsi', 'd':'icecream'}
-	d = {'a':'hamburger', 'c':'pepsi', 'd':'icecream'}
-	e = {'a':'HotDog', 'b':'fries', 'd':'icecream'}
+	diffed = jay_diff_plus({}, {'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}})
+	assert diffed == {'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}
 
-	last = {}
-	diffed = jay_diff_plus(a, {})
-	print(f"a: Plus: {diffed}")
+	diffed = jay_diff_plus({'a':'hamburger', 'b':'fries', 'c':'pepsi'}, {'a':'hamburger', 'b':'fries', 'c':'coke'})
+	assert diffed == {}
 
-	diffed = jay_diff_plus(b, a)
-	print(f"b: Plus: {diffed}")
+	diffed = jay_diff_plus({'a':'hamburger', 'b':'fries', 'c':'pepsi', 'd':'icecream'},  {'a':'hamburger', 'b':'fries', 'c':'pepsi'})
+	assert diffed == {}
 
-	diffed = jay_diff_plus(c, b)
-	print(f"c: Plus: {diffed}")
+	diffed = jay_diff_plus({'a':'hamburger', 'b':'fries', 'c':'pepsi'}, {'a':'hamburger', 'd':'icecream', 'c':'coke'})
+	assert diffed == {'d':'icecream'}
 
-	diffed = jay_diff_plus(d, c)
-	print(f"d: Plus: {diffed}")
+	diffed = jay_diff_plus({'a':'hamburger', 'c':'pepsi', 'd':'icecream'}, {'a':'hamburger', 'b':'fries', 'c':'coke'})
+	assert diffed == {'b':'fries'}
 
-	diffed = jay_diff_minus(a, {})
-	print(f"a: Minus: {diffed}")
+	diffed = jay_diff_plus({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke'}}, {'c': {'f': 'coffee'}})
+	assert diffed == {'c': {'f': 'coffee'}}
 
-	diffed = jay_diff_minus(b, a)
-	print(f"b: Minus: {diffed}")
+	diffed = jay_diff_minus({'a':'hamburger', 'c':'pepsi', 'd':'icecream'}, {'a':'hamburger', 'b':'fries', 'c':'coke'})
+	assert diffed == {'d':'icecream'}
 
-	diffed = jay_diff_minus(c, b)
-	print(f"a: Minus: {diffed}")
+	diffed = jay_diff_minus({'a':'hamburger', 'b':'fries', 'c':'coke'}, {'a':'hamburger', 'b':'fries', 'c':'coke'})
+	assert diffed == {}
 
-	diffed = jay_diff_minus(d, c)
-	print(f"d: Minus: {diffed}")
+	diffed = jay_diff_minus({'a':'hamburger', 'b':'fries', 'c':'coke'}, {'a':'hamburger', 'b':'fries', 'c':'pepsi'})
+	assert diffed == {}
 
-	diffed = jay_diff_upd(a, {})
-	print(f"a: Update: {diffed}")
+	diffed = jay_diff_minus({'a':'hamburger', 'b':'fries', 'c':'pepsi'}, {'a':'hamburger', 'b':'fries'})
+	assert diffed == {'c':'pepsi'}
 
-	diffed = jay_diff_upd(b, a)
-	print(f"b: Update: {diffed}")
+	diffed = jay_diff_minus({'a':'hamburger', 'b':'fries', 'c':'pepsi'}, {'a':'hamburger', 'b':'fries', 'c':'coke'})
+	assert diffed == {}
 
-	diffed = jay_diff_upd(c, b)
-	print(f"a: Update: {diffed}")
+	diffed = jay_diff_minus({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hamburger', 'b':'fries'})
+	assert diffed == {'c': {'e': 'coke', 'f': 'coffee'}}
 
-	diffed = jay_diff_upd(d, c)
-	print(f"d: Update: {diffed}")
+	diffed = jay_diff_minus({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'c': {'e': 'coke'}})
+	assert diffed == {'a':'hamburger', 'b':'fries', 'c': {'f': 'coffee'}}
 
-	diffed = jay_diff_full(a, {})
-	print(f"a: Full: {diffed}")
+	diffed = jay_diff_upd({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hotdog', 'b':'potatoes'})
+	assert diffed == {'a':'hotdog', 'b':'potatoes'}
 
-	diffed = jay_diff_full(b, a)
-	print(f"b: Full: {diffed}")
+	diffed = jay_diff_upd({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'c': {'e': 'pepsi'}})
+	assert diffed == {'c': {'e': 'pepsi'}}
 
-	diffed = jay_diff_full(c, b)
-	print(f"c: Full: {diffed}")
+	diffed = jay_diff_upd({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hotdog', 'b':'fries'})
+	assert diffed == {'a':'hotdog'}
 
-	diffed = jay_diff_full(d, c)
-	print(f"d: Full: {diffed}")
+	diffed = jay_diff_upd({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee'}})
+	assert diffed == {'c': {'e': 'pepsi'}}
 
-	diffed = jay_diff_full(e, d)
-	print(f"e: Full: {diffed}")
+	# ToDo: jay_diff_full
 
+	merged = jay_merge_plus({}, {'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}})
+	assert merged == {'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}
 
-	a = {'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}
-	b = {'b':'fries', 'c':'pepsi'}
-	c = {'d':'icecream'}
-	d = {'c': {'f': 'coffee'}}
+	merged = jay_merge_plus({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'d':'icecream'})
+	assert merged == {'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}, 'd':'icecream'}
 
-	merged = jay_merge_plus({}, a)
-	print(f"a: Plus: {merged}")
+	merged = jay_merge_minus({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}, 'd':'icecream'}, {'d':'icecream'})
+	assert merged == {'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}
 
-	merged = jay_merge_plus(merged, c)
-	print(f"c: Plus: {merged}")
+	merged = jay_merge_minus({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'c': {'f': 'coffee'}})
+	assert merged == {'a':'hamburger', 'b':'fries', 'c': {'e': 'coke'}}
 
-	merged = jay_merge_minus(merged, c)
-	print(f"c: Minus: {merged}")
+	merged = jay_merge_minus({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'c': {'e': 'coke'}})
+	assert merged == {'a':'hamburger', 'b':'fries', 'c': {'f': 'coffee'}}
 
-	merged = jay_merge_minus(merged, d)
-	print(f"d: Minus: {merged}")
+	merged = jay_merge_plus({'a':'hamburger', 'b':'fries', 'c': {'f': 'coffee'}}, {'d':'icecream'})
+	assert merged == {'a':'hamburger', 'b':'fries', 'c': {'f': 'coffee'}, 'd':'icecream'}
 
-	merged = jay_merge_plus(merged, d)
-	print(f"d: Plus: {merged}")
-
-	c = {'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}, 'd':'icecream'}
-	d = {'a':'hamburger', 'c':'pepsi', 'd':'icecream'}
-	e = {'a':'HotDog', 'b':'fries', 'd':'icecream'}
+	merged = jay_merge_plus({'a':'hamburger', 'b':'fries', 'c': {'f': 'coffee'}, 'd':'icecream'}, {'d':'icecream'})
+	assert merged == {'a':'hamburger', 'b':'fries', 'c': {'f': 'coffee'}, 'd':'icecream'}