Solved it myself.
DATA:
lr_entity_customer TYPE REF TO IF_BOL_BO_PROPERTY_ACCESS,
lr_entity_contact TYPE REF TO cl_crm_bol_entity,
lr_iter TYPE REF TO CL_bsp_wd_collection_wrapper,
lr_entity type ref to cl_crm_bol_entity.
lr_iter ?= me->typed_context->contacts->get_collection_wrapper( ).
lr_entity ?= lr_iter->IF_BOL_BO_COL~GET_FIRST( ).
lr_entity->get_properties( IMPORTING es_attributes = lv_contactdetails ).