Clears all CT packages previously registered with register_ct().
After calling clear_ct(), validate() and submit() use
only the bundled CDISC CT.
See also
Other conformance:
adam_rules(),
build_anchor_index(),
fda_rules(),
fetch_core_rules(),
fetch_herald_rules(),
herald_rules_cache_dir(),
list_ct(),
load_herald_config(),
new_herald_context(),
pmda_rules(),
register_ct(),
register_operator(),
rule_catalog(),
rule_config(),
update_core_rules(),
validate(),
validate_spec(),
validate_spec_define(),
validation_report(),
verify_html_report()