code: public Where<T, ID> exists(QueryBuilder<?, ?> subQueryBuilder) {
  		// we do this to turn off the automatic addition of the ID column in the select column list
  		subQueryBuilder.enableInnerQuery();
  		addClause(new Exists(new InternalQueryBuilderWrapper(subQueryBuilder)));
  		return this;
  	}
docs: Add a EXISTS clause with a sub-query inside of parenthesis.
  
  <p>
  <b>NOTE:</b> The sub-query will be prepared at the same time that the outside query is.
  </p>