code: def trace_read(self, offset, num_items):
          
          buf_size = ctypes.c_uint32(num_items)
          buf = (structs.JLinkTraceData * num_items)()
          res = self._dll.JLINKARM_TRACE_Read(buf, int(offset), ctypes.byref(buf_size))
          if (res == 1):
              raise errors.JLinkException('Failed to read from trace buffer.')
          return list(buf)[:int(buf_size.value)]
docs: Reads data from the trace buffer and returns it.
  
          Args:
            self (JLink): the ``JLink`` instance.
            offset (int): the offset from which to start reading from the trace
              buffer.
            num_items (int): number of items to read from the trace buffer.
  
          Returns:
            A list of ``JLinkTraceData`` instances corresponding to the items
            read from the trace buffer.  Note that this list may have size less
            than ``num_items`` in the event that there are not ``num_items``
            items in the trace buffer.
  
          Raises:
            JLinkException: on error.