public EmuUnixFileDescriptor<T> putDescriptor(int fd, EmuUnixFileDescriptor<T> desc) {
		synchronized (descriptors) {
			return descriptors.put(fd, desc);
		}
	}
Put a descriptor into the process' open file handles

@param fd the file descriptor value
@param desc the simulated descriptor (handle, console, etc.)
@return the previous descriptor, which probably ought to be {@code null}
Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/emu/unix/AbstractEmuUnixSyscallUseropLibrary.java