add a pagingListener interface
Revert "add a pagingListener interface"

This reverts commit 62020c5eb690b9c3668cb9cd077040b6c4041835.
Revert "Revert "add a pagingListener interface""

This reverts commit 8b0a1c6d48f084b4852e88ef1b0498b4893189b8.
looking for the good cut for modifying the fetch size