A.8.1.2. wl_data_offer::receive - request that the data is transferred
To transfer the offered data, the client issues this request and indicates the mime-type it wants to receive. The transfer happens through the passed fd (typically a pipe(7) file descriptor). The source client writes the data in the mime-type representation requested and then closes the fd. The receiving client reads from the read end of the pipe until EOF and the closes its end, at which point the transfer is complete.