hash as an search key and hash collision

I want to maintain an internal table which the primary key is sql_text and
planstmt::text, it is efficient since it both may be very long. So a
general
idea is to use sql_hash_value and plan_hash_value. Then we have to
handle the hash collision case. However I checked the codes both in
sr_plans[1]
and pg_stat_statements[2], both of them didn't handle such cases, IIUC. so
how can I understand this situation?

[1]
https://github.com/postgrespro/sr_plan/blob/41d96bf136ec072dac77dddf8d9765bba39190ff/sr_plan.c#L383
[2]
https://github.com/postgres/postgres/blob/master/contrib/pg_stat_statements/pg_stat_statements.c#L154

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Best Regards
Andy Fan