code: public com.google.api.ads.adwords.axis.v201809.cm.SystemManagedEntitySource getSystemManagedEntitySource() {
          return systemManagedEntitySource;
      }
docs: Gets the systemManagedEntitySource value for this Ad.
  
  @return systemManagedEntitySource   * The source of this system-managed ad.
  <span class="constraint Selectable">This field can
  be selected using the value "SystemManagedEntitySource".</span><span
  class="constraint Filterable">This field can be filtered on.</span>
  <span class="constraint ReadOnly">This field is read only and will
  be ignored when sent to the API.</span>