Javadoc
applyRowFilterAndColumnMasking is called once for each table in a query.
(part 1) It expects a valid filter condition to be returned. Null indicates no filtering is
required.
Example: table foo(c int) -> "c > 0 && c % 2 = 0"
(part 2) It expects a valid expression as used in a select clause. Null
is NOT a valid option. If no transformation is needed simply return the
column name.
Example: column a -> "a" (no transform)
Example: column a -> "reverse(a)" (call the reverse function on a)
Example: column a -> "5" (replace column a with the constant 5)