final TestableUnixStylePermission permission = new TestableUnixStylePermission(mockSecurityManager, ownerId, ownerGroupId, mode);
final long permissionVector = permission.getVector_testable();
//expectations
mockOstream.writeLong(permissionVector);
expect(mockIstream.readLong()).andReturn(permissionVector);
replay(mockSecurityManager, mockOstream, mockIstream);
permission.write(mockOstream);