Representation of type Array cannot be merged

[GuangChenPidouki]

class definition:
class:Order

class OrderAsk < Order has_many :trades

api call:
orders_new = present orders, with: APIv2::Entities::OrderEntity unless orders.empty?

so, if orders has one or more orders that has multiple trades (trade number > 1), it is likely that above present api call would fail with error: Representation of type Array cannot be merged

And in my entity class, there is no code about trades used

Is there an issue for this case?
Or is there a workaround to use a entity for a list of record, which contain some has_many relation