update readme

Author: Muhammad Hashim

README.md

@@ -45,7 +45,7 @@ An advanced example:
     });
 
     try {
-    ProcessMonitor pMonitor = CommandExecutor.execute(cmd, eop); //execute the command, redirect the output to eop.
+    ProcessMonitor pMonitor = CommandExecutor.execute(cmd, null, eop); //execute the command, redirect the output to eop.
     ExecutionReport report = pMonitor.getExecutionReport(); //blocks until the process finishes or gets aborted.
 
     String commandLine = cmd.string();