code: public void setMobileDeviceSegment(com.google.api.ads.admanager.axis.v201808.MobileDeviceTargeting mobileDeviceSegment) {
          this.mobileDeviceSegment = mobileDeviceSegment;
      }
docs: Sets the mobileDeviceSegment value for this ProductSegmentation.
  
  @param mobileDeviceSegment   * The mobile device segmentation. {@link MobileDeviceTargeting#excludedMobileDevices}
  must be
  empty or null.
  
  <p>This attribute is optional.