Generating "Subplan Removed" in EXPLAIN

Our document states that EXPLAIN can generate "Subplan Removed":

    https://www.postgresql.org/docs/current/ddl-partitioning.html#DDL-PARTITION-PRUNING

    It is possible to determine the number of partitions which were removed
    during this phase by observing the “Subplans Removed” property in the
    EXPLAIN output.

However, I can't figure out how to generate that string in EXPLAIN
output.  I tried many examples and searched the web for examples but I
can't generate it in queries using git master.

For example, this website:

    https://gist.github.com/amitlan/cd13271142bb2d26ae46b69afb675a31

has several EXPLAIN examples that show "Subplan Removed" but running the
queries in git master doesn't generate it for me.

Does anyone know how to generate this?  Thanks.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

Embrace your flaws.  They make you human, rather than perfect,
which you will never be.