public String toString() {
            StringBuilder builder = new StringBuilder();
            String[] args = execString();
            for (String s : args) {
                if (s.indexOf(' ') >= 0) {
                    builder.append('"').append(s).append('"');
                } else {
                    builder.append(s);
                }
                builder.append(' ');
            }
            return builder.toString();
        }
Returns the commands of this instance.
Arguments with spaces in are presented with quotes round; other
arguments are presented raw

@return a string representation of the object.
clients/src/main/java/org/apache/kafka/common/utils/Shell.java