code: public com.google.api.ads.adwords.axis.v201809.rm.Rule getRule() {
          return rule;
      }
docs: Gets the rule value for this ExpressionRuleUserList.
  
  @return rule   * Boolean rule that defines this user list. The rule consists
  of a list of rule item groups and
  each rule item group consists of a list of rule
  items.
  All the rule item groups are ORed together for
  evaluation before version V201705.
  Starting from version V201705, the group operator
  is based on {@link Rule#getRuleType()}.
  This field is selected by default.
  <span class="constraint Selectable">This field
  can be selected using the value "ExpressionListRule".</span>
  <span class="constraint Required">This field is
  required and should not be {@code null} when it is contained within
  {@link Operator}s : ADD.</span>