comment 2)
Analysis:
flag to check unique gets reset every time. Hence unique values cannot be
correctly checked
Fix:
do not reset the flag that checks unique for null, true and false
values.

comment 3)
Analysis:
current implementation checks for appropriate value but does not
return true.
Fix:
return true on error

comment 4)
Analysis:
Current implementation did not check for value type for values
inside required array.
Fix:
Check values inside required array