code: public void setOperatingSystemSegment(com.google.api.ads.admanager.axis.v201808.OperatingSystemTargeting operatingSystemSegment) {
          this.operatingSystemSegment = operatingSystemSegment;
      }
docs: Sets the operatingSystemSegment value for this ProductSegmentation.
  
  @param operatingSystemSegment   * The operating system segmentation. {@link OperatingSystemTargeting#isTargeted}
  must be {@code true}.
  We only allow segment by Operating_System, not Operating_System_Version
  (will be ignored).
  
  <p>This attribute is optional.