code: public ListUsersResult withUserList(User... userList) {
          if (this.userList == null) {
              setUserList(new java.util.ArrayList<User>(userList.length));
          }
          for (User ele : userList) {
              this.userList.add(ele);
          }
          return this;
      }
docs: <p>
  The list of users.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setUserList(java.util.Collection)} or {@link #withUserList(java.util.Collection)} if you want to override
  the existing values.
  </p>
  
  @param userList
  The list of users.
  @return Returns a reference to this object so that method calls can be chained together.