code: @Override
      InputStream execute(String cmd, Object ... args) throws AgentLoadException, IOException {
          assert args.length <= 3;                // includes null
  
          // first check that we are still attached
          int door;
          synchronized (this) {
              if (fd == -1) {
                  throw new IOException("Detached from target VM");
              }
              door = fd;
          }
  
          // enqueue the command via a door call
          int s = enqueue(door, cmd, args);
          assert s >= 0;                          // valid file descriptor
  
          // The door call returns a file descriptor (one end of a socket pair).
          // Create an input stream around it.
          SocketInputStream sis = new SocketInputStream(s);
  
          // Read the command completion status
          int completionStatus;
          try {
              completionStatus = readInt(sis);
          } catch (IOException ioe) {
              sis.close();
              throw ioe;
          }
  
          // If non-0 it means an error but we need to special-case the
          // "load" command to ensure that the right exception is thrown.
          if (completionStatus != 0) {
              sis.close();
              if (cmd.equals("load")) {
                  throw new AgentLoadException("Failed to load agent library");
              } else {
                  throw new IOException("Command failed in target VM");
              }
          }
  
          // Return the input stream so that the command output can be read
          return sis;
      }
docs: Execute the given command in the target VM.