DB<4> push $hash{key}[4]{array}->@* , 1..3

  DB<5> x \%hash
0  HASH(0xb400007bea0f2180)
   'key' => ARRAY(0xb400007bea0f22a0)
      0  empty slot
      1  empty slot
      2  empty slot
      3  empty slot
      4  HASH(0xb400007bea0f22d0)
         'array' => ARRAY(0xb400007bea0f1d08)
            0  1
            1  2
            2  3
  DB<6>