@@ -1143,33 +1143,34 @@ def test_boxed_value_type_mutation_result():
     # to accidentally write code like the following which is not really
     # mutating value types in-place but changing boxed copies.
 
-    from System.Drawing import Point
+    # Uses ValueType DictionaryEntry instead of Point
+    from System.Collections import DictionaryEntry
     from System import Array
 
-    items = Array.CreateInstance(Point, 5)
+    items = Array.CreateInstance(DictionaryEntry, 5)
 
     for i in range(5):
-        items[i] = Point(i, i)
+        items[i] = DictionaryEntry(i, i)
 
     for i in range(5):
         # Boxed items, so set_attr will not change the array member.
-        assert items[i].X == i
-        assert items[i].Y == i
-        items[i].X = i + 1
-        items[i].Y = i + 1
-        assert items[i].X == i
-        assert items[i].Y == i
+        assert items[i].Key == i
+        assert items[i].Value == i
+        items[i].Key = i + 1
+        items[i].Value = i + 1
+        assert items[i].Key == i
+        assert items[i].Value == i
 
     for i in range(5):
         # Demonstrates the workaround that will change the members.
-        assert items[i].X == i
-        assert items[i].Y == i
+        assert items[i].Key == i
+        assert items[i].Value == i
         item = items[i]
-        item.X = i + 1
-        item.Y = i + 1
+        item.Key = i + 1
+        item.Value = i + 1
         items[i] = item
-        assert items[i].X == i + 1
-        assert items[i].Y == i + 1
+        assert items[i].Key == i + 1
+        assert items[i].Value == i + 1
 
 
 def test_special_array_creation():
 
@@ -61,26 +61,28 @@ def test_non_public_class():
 
 def test_basic_subclass():
     """Test basic subclass of a managed class."""
-    from System.Collections import Hashtable
+    # Uses ArrayList instead of Hashtable
+    # As it's available from .Net Core 2.0 without an addref
+    from System.Collections import ArrayList
 
-    class MyTable(Hashtable):
+    class MyArrayList(ArrayList):
         def how_many(self):
             return self.Count
 
-    table = MyTable()
+    array_list = MyArrayList()
 
-    assert table.__class__.__name__.endswith('MyTable')
-    assert type(table).__name__.endswith('MyTable')
-    assert len(table.__class__.__bases__) == 1
-    assert table.__class__.__bases__[0] == Hashtable
+    assert array_list.__class__.__name__.endswith('MyArrayList')
+    assert type(array_list).__name__.endswith('MyArrayList')
+    assert len(array_list.__class__.__bases__) == 1
+    assert array_list.__class__.__bases__[0] == ArrayList
 
-    assert table.how_many() == 0
-    assert table.Count == 0
+    assert array_list.how_many() == 0
+    assert array_list.Count == 0
 
-    table.set_Item('one', 'one')
+    array_list.Add('one')
 
-    assert table.how_many() == 1
-    assert table.Count == 1
+    assert array_list.how_many() == 1
+    assert array_list.Count == 1
 
 
 def test_subclass_with_no_arg_constructor():
@@ -118,21 +120,23 @@ def __init__(self, v):
 
 def test_struct_construction():
     """Test construction of structs."""
-    from System.Drawing import Point
+    # Uses DateTime instead of Point
+    # As it's available from .Net Core 2.0 without an addref
+    from System import DateTime
 
-    p = Point()
-    assert p.X == 0
-    assert p.Y == 0
+    dt1 = DateTime(2017, 2, 27)
+    assert dt1.Day == 27
+    assert dt1.Month == 2
+    assert dt1.Year == 2017
 
-    p = Point(0, 0)
-    assert p.X == 0
-    assert p.Y == 0
+    # Static method calls default constructor
+    dt2 = DateTime.MinValue
+    assert dt2.Day == 1
+    assert dt2.Month == 1
+    assert dt2.Year == 1
 
-    p.X = 10
-    p.Y = 10
-
-    assert p.X == 10
-    assert p.Y == 10
+    # mutation tests removed
+    # structs are not typically mutable
 
     # test strange __new__ interactions
 
@@ -169,44 +173,53 @@ def test_ienumerator_iteration():
 
 def test_override_get_item():
     """Test managed subclass overriding __getitem__."""
-    from System.Collections import Hashtable
-
-    class MyTable(Hashtable):
+    from System.Collections import ArrayList
+    
+    # Uses ArrayList instead of Hashtable
+    # As it's available from .Net Core 2.0 without an addref
+    class MyArrayList(ArrayList):
         def __getitem__(self, key):
-            value = Hashtable.__getitem__(self, key)
+            value = ArrayList.__getitem__(self, key)
             return 'my ' + str(value)
 
-    table = MyTable()
-    table['one'] = 'one'
-    table['two'] = 'two'
-    table['three'] = 'three'
+    array_list = MyArrayList()
+    array_list.Add('zero')
+    array_list.Add('one')
+    array_list.Add('two')
 
-    assert table['one'] == 'my one'
-    assert table['two'] == 'my two'
-    assert table['three'] == 'my three'
+    assert array_list[0] == 'my zero'
+    assert array_list[1] == 'my one'
+    assert array_list[2] == 'my two'
 
-    assert table.Count == 3
+    assert array_list.Count == 3
 
 
 def test_override_set_item():
     """Test managed subclass overriding __setitem__."""
-    from System.Collections import Hashtable
-
-    class MyTable(Hashtable):
+    from System.Collections import ArrayList
+    
+    # Uses ArrayList instead of Hashtable
+    # As it's available from .Net Core 2.0 without an addref
+    class MyArrayList(ArrayList):
         def __setitem__(self, key, value):
-            value = 'my ' + str(value)
-            Hashtable.__setitem__(self, key, value)
-
-    table = MyTable()
-    table['one'] = 'one'
-    table['two'] = 'two'
-    table['three'] = 'three'
-
-    assert table['one'] == 'my one'
-    assert table['two'] == 'my two'
-    assert table['three'] == 'my three'
-
-    assert table.Count == 3
+            value = 'your ' + str(value)
+            ArrayList.__setitem__(self, key, value)
+
+    array_list = MyArrayList()
+    # need to add three items first
+    array_list.Add("a")
+    array_list.Add("b")
+    array_list.Add("c")
+    
+    array_list[0] = 'zero'
+    array_list[1] = 'one'
+    array_list[2] = 'two'
+
+    assert array_list[0] == 'your zero'
+    assert array_list[1] == 'your one'
+    assert array_list[2] == 'your two'
+
+    assert array_list.Count == 3
 
 
 def test_add_and_remove_class_attribute():
 
@@ -112,13 +112,15 @@ def test_simple_import_from_with_alias():
 
 def test_dotted_name_import_from():
     """Test dotted-name 'import from'."""
-    from CLR.System import Xml
-    assert is_clr_module(Xml)
-    assert Xml.__name__ == 'System.Xml'
+    # Uses IO instead of Xml
+    # As it's available from .Net Core 2.0 without an addref
+    from CLR.System import IO
+    assert is_clr_module(IO)
+    assert IO.__name__ == 'System.IO'
 
-    from CLR.System.Xml import XmlDocument
-    assert is_clr_class(XmlDocument)
-    assert XmlDocument.__name__ == 'XmlDocument'
+    from CLR.System.IO import Path
+    assert is_clr_class(Path)
+    assert Path.__name__ == 'Path'
 
     from xml.dom import pulldom
     assert isinstance(pulldom, types.ModuleType)
@@ -131,13 +133,15 @@ def test_dotted_name_import_from():
 
 def test_dotted_name_import_from_with_alias():
     """Test dotted-name 'import from' with aliasing."""
-    from CLR.System import Xml as myXml
-    assert is_clr_module(myXml)
-    assert myXml.__name__ == 'System.Xml'
+    # Uses IO instead of Xml
+    # As it's available from .Net Core 2.0 without an addref
+    from CLR.System import IO as myIO
+    assert is_clr_module(myIO)
+    assert myIO.__name__ == 'System.IO'
 
-    from CLR.System.Xml import XmlDocument as myXmlDocument
-    assert is_clr_class(myXmlDocument)
-    assert myXmlDocument.__name__ == 'XmlDocument'
+    from CLR.System.IO import Path as myPath
+    assert is_clr_class(myPath)
+    assert myPath.__name__ == 'Path'
 
     from xml.dom import pulldom as myPulldom
     assert isinstance(myPulldom, types.ModuleType)
@@ -151,13 +155,15 @@ def test_dotted_name_import_from_with_alias():
 def test_from_module_import_star():
     """Test from module import * behavior."""
     count = len(locals().keys())
-    m = __import__('CLR.System.Management', globals(), locals(), ['*'])
-    assert m.__name__ == 'System.Management'
+    # Uses IO instead of Xml
+    # As it's available from .Net Core 2.0 without an addref
+    m = __import__('CLR.System.IO', globals(), locals(), ['*'])
+    assert m.__name__ == 'System.IO'
     assert is_clr_module(m)
     assert len(locals().keys()) > count + 1
 
-    m2 = __import__('System.Management', globals(), locals(), ['*'])
-    assert m2.__name__ == 'System.Management'
+    m2 = __import__('System.IO', globals(), locals(), ['*'])
+    assert m2.__name__ == 'System.IO'
     assert is_clr_module(m2)
     assert len(locals().keys()) > count + 1
 
@@ -168,16 +174,22 @@ def test_explicit_assembly_load():
     """Test explicit assembly loading using standard CLR tools."""
     from CLR.System.Reflection import Assembly
     from CLR import System
+    from CLR.System.IO import FileNotFoundException
     import sys
 
-    assembly = Assembly.LoadWithPartialName('System.Data')
+    assembly = Assembly.LoadWithPartialName('System.IO')
     assert assembly is not None
+    # Uses IO instead of Data
+    # As it's available from .Net Core 2.0 without an addref
+    import CLR.System.IO
+    assert 'System.IO' in sys.modules
 
-    import CLR.System.Data
-    assert 'System.Data' in sys.modules
-
-    assembly = Assembly.LoadWithPartialName('SpamSpamSpamSpamEggsAndSpam')
-    assert assembly is None
+    # Assembly.LoadWithPartialName is obsolete, and delegates to Assembly.Load
+    # in .Net Core (which then throws)
+    # assembly = Assembly.LoadWithPartialName('SpamSpamSpamSpamEggsAndSpam')
+    # assert assembly is None
+    with pytest.raises(FileNotFoundException):
+        assembly = Assembly.LoadFrom('SpamSpamSpamSpamEggsAndSpam')
 
 
 def test_implicit_load_already_valid_namespace():
@@ -224,8 +236,9 @@ def test_module_get_attr():
 
     int_type = System.Int32
     assert is_clr_class(int_type)
-
-    module = System.Xml
+    # Uses IO instead of Xml
+    # As it's available from .Net Core 2.0 without an addref
+    module = System.IO
     assert is_clr_module(module)
 
     with pytest.raises(AttributeError):
 
@@ -141,8 +141,9 @@ def test_interface_property():
     """Test properties of interfaces. Added after a bug report
        that an IsAbstract check was inappropriate and prevented
        use of properties when only the interface is known."""
-    from System.Collections import Hashtable, ICollection
-
-    mapping = Hashtable()
-    coll = ICollection(mapping)
-    assert coll.Count == 0
+    from System.Collections import ArrayList, IList
+    # Uses ArrayList instead of Hashtable
+    # As it's available from .Net Core 2.0 without an addref
+    mapping = ArrayList()
+    lst = IList(mapping)
+    assert lst.Count == 0