presto-parser/src/main/java/io/prestosql/sql/ExpressionFormatter.java/ExpressionFormatter/visitDereferenceExpression
class ExpressionFormatter:        @Override
        protected String visitDereferenceExpression(DereferenceExpression node, Void context)
        {
            String baseString = process(node.getBase(), context);
            return baseString + "." + process(node.getField());
        }