code: public void setGroupBy(java.util.Collection<GroupDefinition> groupBy) {
          if (groupBy == null) {
              this.groupBy = null;
              return;
          }
  
          this.groupBy = new java.util.ArrayList<GroupDefinition>(groupBy);
      }
docs: <p>
  Groups only by <code>SUBSCRIPTION_ID</code>. Metadata is included.
  </p>
  
  @param groupBy
  Groups only by <code>SUBSCRIPTION_ID</code>. Metadata is included.