A data provider class (DPC) provides the business data access of your service. It must inherit from super class /IWBEP/CL_V4_ABS_DATA_PROVIDER.
/IWBEP/IF_V4_DP_BASIC
/IWBEP/IF_V4_DP_INTERMEDIATE
/IWBEP/IF_V4_DP_ADVANCED
/IWBEP/IF_V4_DP_BATCH
/IWBEP/IF_V4_DP_PROCESS_STEPS