Problem when creating deep entity functionality

Hi experts,

I have a problem when creating deep entity for my service.

I have 2 entity Types :

* Dealer

* Bank

I have 2 entity Sets :

* Dealers

* Banks

The relationships of (Dealer : Bank) is 1 : N

I redefined /IWBEP/IF_MGW_APPL_SRV_RUNTIME~CREATE_DEEP_ENTITY method.

by calling the following method

call method io_data_provider->read_entry_data( importing es_data = ls_data ).

then I execute 'POST' from gateway client

'/sap/opu/odata/sap/ZMASTERDATA_SRV/Dealers'

with XML request that has 1 Dealer and 2 banks data.

and I got the error message 'Method 'DEALERS_CREATE_ENTITY' not implemented in data provider class'

the thing that I do not understand - how the system will know to call 'Deep Entity' method instead of 'Create Entity' ?

do I need to implement 'Create Entity' method in this case ?

Really appreciate your help !!

Please let me know if you need more information from me.