@Test
	public void testSimpleUnion() throws Exception {

		UnionDataType union = new UnionDataType(CategoryPath.ROOT, "union", dataMgr);

		// NOTE: preference will be given to packing compatible bitfields at same byte
		// offset into structures (currently ambiguous data in PDB xml)

		//@formatter:off
		List<MyPdbMember> members =
			CollectionUtils.asList(new MyPdbMember("a", "uchar", 0),
				new MyPdbMember("b:0x4:0x0", "uchar", 0),
				new MyPdbMember("c:0x4:0x4", "uchar", 0),
				new MyPdbMember("d:0x4:0x0", "uchar", 0),
				new MyPdbMember("e:0x4:0x4", "uchar", 0),
				new MyPdbMember("f", "ushort", 0));
		//@formatter:on

		assertTrue(DefaultCompositeMember.applyDataTypeMembers(union, false, false, 2, members,
			this, TaskMonitor.DUMMY));

		// NOTE: handling of bit-fields within union is rather ambiguous within
		// PDB data

		//@formatter:off
		CompositeTestUtils.assertExpectedComposite(this,
			"/union\n" +
			"pack()\n" +
			"Union union {\n" +
			"   0   uchar   1   a   \"\"\n" +
			"   0   union_s_1   1   _s_1   \"\"\n" +
			"   0   union_s_2   1   _s_2   \"\"\n" +
			"   0   ushort   2   f   \"\"\n" +
			"}\n" +
			"Length: 2 Alignment: 2\n" +
			"/union/union_s_1\n" +
			"pack()\n" +
			"Structure union_s_1 {\n" +
			"   0   uchar:4(0)   1   b   \"\"\n" +
			"   0   uchar:4(4)   1   c   \"\"\n" +
			"}\n" +
			"Length: 1 Alignment: 1\n" +
			"/union/union_s_2\n" +
			"pack()\n" +
			"Structure union_s_2 {\n" +
			"   0   uchar:4(0)   1   d   \"\"\n" +
			"   0   uchar:4(4)   1   e   \"\"\n" +
			"}\n" +
			"Length: 1 Alignment: 1", union, true);
			//@formatter:on
	}
Structure Source ***
		
		 struct BitFieldUnionAlternatingPadded_s {
		   union {
		      struct {
		         char a0:1;
		         char :1;
		         char a2:1;
		         char :1;
		         char a4:1;
		         char :1;
		      };
		      struct {
		         char :1;
		         char a1:1;
		         char :1;
		         char a3:1;
		         char :1;
		         char a5:1;
		      };
		   };
		};
Ghidra/Features/PDB/src/test/java/ghidra/app/util/bin/format/pdb/CompositeMemberTest.java