load fails on finding additional attributes

[hlms]

This line: https://github.com/Veraticus/Dynamoid/blob/master/lib/dynamoid/fields.rb#L4 says:

All fields on a Dynamoid::Document must be explicitly defined -- if you have fields in the database that are not specified with field, then they will be ignored.

But when I had additional fields in DynamoDB, I got exception:

NoMethodError: undefined method `my_additional_field=' for #<MyTable:0xa6dddc8>

        from activemodel-3.2.19/lib/active_model/attribute_methods.rb:407:in `method_missing'
        from dynamoid-0.6.1.1/lib/dynamoid/document.rb:123:in `block in load'
        from dynamoid-0.6.1.1/lib/dynamoid/document.rb:123:in `each'
        from dynamoid-0.6.1.1/lib/dynamoid/document.rb:123:in `load'
        from dynamoid-0.6.1.1/lib/dynamoid/document.rb:118:in `block in initialize'
        from activesupport-3.2.19/lib/active_support/callbacks.rb:403:in `_run__356022796__initialize__809605463__callbacks'
        from activesupport-3.2.19/lib/active_support/callbacks.rb:405:in `__run_callback'
        from activesupport-3.2.19/lib/active_support/callbacks.rb:385:in `_run_initialize_callbacks'
        from activesupport-3.2.19/lib/active_support/callbacks.rb:81:in `run_callbacks'
        from dynamoid-0.6.1.1/lib/dynamoid/document.rb:111:in `initialize'
        from dynamoid-0.6.1.1/lib/dynamoid/persistence.rb:61:in `new'
        from dynamoid-0.6.1.1/lib/dynamoid/persistence.rb:61:in `from_database'
        from dynamoid-0.6.1.1/lib/dynamoid/identity_map.rb:19:in `from_database'
        from dynamoid-0.6.1.1/lib/dynamoid/dirty.rb:8:in `from_database'
        from dynamoid-0.6.1.1/lib/dynamoid/finders.rb:60:in `find_by_id'
        from dynamoid-0.6.1.1/lib/dynamoid/identity_map.rb:35:in `find_by_id'
        from dynamoid-0.6.1.1/lib/dynamoid/finders.rb:28:in `find'
        from dynamoid-0.6.1.1/lib/dynamoid/document.rb:154:in `reload'
        from (irb):5