Implemented Flyweight design pattern.

tests/structural_tests/test_flyweight.py

@@ -0,0 +1,32 @@
+from unittest import TestCase
+from pypatterns.structural.flyweight import FlyweightMeta
+
+
+class FlyweightMetaTestCase(TestCase):
+    """
+    Unit testing class for the FlyweightMeta class.
+    """
+    def setUp(self):
+        """
+        Initialize testing data.
+        """
+        class Card(object, metaclass=FlyweightMeta):
+
+            def __init__(self, suit, value):
+                self.suit = suit
+                self.value = value
+
+        self.card_class = Card
+
+    def test_flyweight(self):
+        """
+        Test that new objects with the same params are actually equal.
+
+        @raise AssertionError: If the test fails.
+        """
+        three_of_spades = self.card_class('Spade', 3)
+        four_of_spades = self.card_class('Spade', 4)
+        three_of_spades_two = self.card_class('Spade', 3)
+
+        self.assertEqual(id(three_of_spades), id(three_of_spades_two))
+        self.assertNotEqual(id(three_of_spades), id(four_of_spades))