remove unnecessary cast
attempt to refactor AbstractMetricWriter and UniqueCountMetricWriter
remove adding separator which will cause a bug
add separator at appopriate places
remove duplicate code in UniqueCountWriter
atempt to remove fileDownloadReport's duplicated code
replace reportWriter with UniqueCountWriter
commit changes to revert to previous commit
Revert f4fe57c..ab22c6c

This rolls back to commit f4fe57cea53087177aad57f2e07271caa4f7a2f5.
Revert aa1d5c3..2ee608a

This rolls back to commit aa1d5c3ce192ca905066be201be0f84ba8442ee3.
Revert f4fe57c..4eb097a

This rolls back to commit f4fe57cea53087177aad57f2e07271caa4f7a2f5.
change getAllReport logic
add separator at appropriate place
fix bug in test
remove unnecessary methods
fix bug
remove unused code
remove println statements and commented code
remove duplicated code in UniqueCountDaoImpl
delete commented code