Test coverage for Partitioned Region clear with Overflow enabled

Using TDD ensure that clear operations are successful when the partitioned regions have overflow enabled.

Make the code changes required to enable this.

Acceptance :

• Passing DUnit tests where clear operations are successful on partitioned region with overflow enabled.
• Ensure that data has overflown when the clear operation is executed and in the end everything is cleared.
• These tests should have redundancy of more than zero 
• Test coverage to when a member departs in this scenario
• Test coverage to when a member restarts in this scenario
• Unit tests with complete code coverage for the newly written code.

Note:
analyze if these tests are needed for offheap?