Tracing: 
ARRAY(0x7fdc5307b7c8) -> HASH(0x7fdc5282e280) -> HASH(0x7fdc5282de48) -> HASH(0x7fdc5282dd88)
[{ box => { a => { b => 2, c => 3 }, y => { z => 1 } } }]

Tracing: 
ARRAY(0x7fdc530b1f18) -> HASH(0x7fdc530b4bc0) -> HASH(0x7fdc530251a0) -> HASH(0x7fdc53025170)
[{ box => { a => { b => 2, c => 3 }, y => {} } }]

Tracing: 
ARRAY(0x7fdc530b4bc0) -> HASH(0x7fdc52846220) -> HASH(0x7fdc5282def0) -> HASH(0x7fdc5282dd70)
[
  { box => { a => { b => 2, c => 3 }, w => "x", y => { z => 2 } } },
]

Tracing: 
ARRAY(0x7fdc530b8a48) -> HASH(0x7fdc53025188) -> HASH(0x7fdc530b1ee8) -> HASH(0x7fdc530b7968)
[{ box => { a => { b => 2, c => 3 }, y => {} } }]

Tracing: 
ARRAY(0x7fdc530b8a48) -> HASH(0x7fdc5282dda0) -> HASH(0x7fdc53094b50) -> HASH(0x7fdc5282de48)
[
  { box => { a => { b => 2, c => 3, d => 4 }, y => { z => 3 } } },
]

Tracing: 
ARRAY(0x7fdc530b1f48) -> HASH(0x7fdc530b7a88) -> HASH(0x7fdc530aabb0) -> HASH(0x7fdc530b1e58)
[{ box => { a => { b => 2, c => 3 }, y => {} } }]