>> a = ['thing', 'another thing', 'more thing']
=> ["thing", "another thing", "more thing"]
>> a.hash
=> -116267152
>> a << 'new thing'
=> ["thing", "another thing", "more thing", "new thing"]
>> a.hash
=> 816923262
>> a.delete 'new thing'
=> "new thing"
>> a
=> ["thing", "another thing", "more thing"]
>> a.hash
=> -116267152
>>