code: def execute_command(self, sock_info, generator, write_concern):
          
          # nModified is only reported for write commands, not legacy ops.
          full_result = {
              "writeErrors": [],
              "writeConcernErrors": [],
              "nInserted": 0,
              "nUpserted": 0,
              "nMatched": 0,
              "nModified": 0,
              "nRemoved": 0,
              "upserted": [],
          }
          op_id = _randint()
          db_name = self.collection.database.name
          listeners = self.collection.database.client._event_listeners
  
          for run in generator:
              cmd = SON([(_COMMANDS[run.op_type], self.collection.name),
                         ('ordered', self.ordered)])
              if write_concern.document:
                  cmd['writeConcern'] = write_concern.document
              if self.bypass_doc_val and sock_info.max_wire_version >= 4:
                  cmd['bypassDocumentValidation'] = True
  
              bwc = _BulkWriteContext(db_name, cmd, sock_info, op_id, listeners)
              results = _do_batched_write_command(
                  self.namespace, run.op_type, cmd,
                  run.ops, True, self.collection.codec_options, bwc)
  
              _merge_command(run, full_result, results)
              # We're supposed to continue if errors are
              # at the write concern level (e.g. wtimeout)
              if self.ordered and full_result['writeErrors']:
                  break
  
          if full_result["writeErrors"] or full_result["writeConcernErrors"]:
              if full_result['writeErrors']:
                  full_result['writeErrors'].sort(
                      key=lambda error: error['index'])
              raise BulkWriteError(full_result)
          return full_result
docs: Execute using write commands.