Function includes

packages/sql/src/AbstractSqlDriver.ts:1708–1708

(arr: T[][], item: T[])

      const pks = wrapped.getPrimaryKeys(true)!;
      const snap = coll.getSnapshot();
      const includes = <T>(arr: T[][], item: T[]) => !!arr.find(i => this.comparePrimaryKeyArrays(i, item));
      // For union-target polymorphic M:N, prepend the per-row discriminator value so the pivot
      // persister can write it alongside the FK id. Memoized per sync-run because a collection can
      // hold hundreds of items of the same few types, and findDiscriminatorValue walks the prototype