*
* The second way is to ask mainloop to read or write a buffer of data. You
* provide a `read_done` or `write_done` handler respectively and call @file_read()
* or @file_write(). This is handy for data connections where you need to transfer
* data between two endpoints or for binary connections where the size of message
*
* The second way is to ask mainloop to read or write a buffer of data. You
* provide a `read_done` or `write_done` handler respectively and call @file_read()
* or @file_write(). This is handy for data connections where you need to transfer
* data between two endpoints or for binary connections where the size of message