code: public boolean hasChild(Account account) {
          for (Account child : children) {
              if (child.equals(account))
                  return true;
          }
          return false;
      }
docs: Tests if an account is a direct child of this account.
  
  @param account check if the passed in account is a child of 'this' account
  @return true if given account is a child of 'this' account