<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def set_std_streams_blocking():
 """ Set stdout and stderr to be blocking. This is called after Popen.communicate() to revert stdout and stderr back to be blocking (the default) in the event that the process to which they were passed manipulated one or both file descriptors to be non-blocking. """

    if not fcntl:
        return
    for f in (sys.__stdout__, sys.__stderr__):
        fileno = f.fileno()
        flags = fcntl.fcntl(fileno, fcntl.F_GETFL)
        fcntl.fcntl(fileno, fcntl.F_SETFL, flags & ~os.O_NONBLOCK)