wal_consistency_checking was added in PostgreSQL 10.
wal_consistency_checking is intended for use by developers, and as it is very resource-intensive, should only be enabled when required.
wal_consistency_checking can be used in regression tests by including it in the variable
PG_TEST_EXTRA, which will cause it to be used in
027_stream_regress.pl. See the Additional Test Suites section of the PostgreSQL documentation for more details.