code: public final ExpectBuilder withTimeout(long duration, TimeUnit unit) {
          validateDuration(duration);
          this.timeout = unit.toMillis(duration);
          return this;
      }
docs: Sets the default timeout in the given unit for expect operations. Optional,
  the default value is 30 seconds.
  
  @param duration the timeout value
  @param unit     the time unit
  @return this
  @throws java.lang.IllegalArgumentException if the timeout {@code <= 0}