presto-main/src/main/java/io/prestosql/sql/analyzer/Field.java/Field/toString
class Field:    @Override
    public String toString()
    {
        StringBuilder result = new StringBuilder();
        if (relationAlias.isPresent()) {
            result.append(relationAlias.get())
                    .append(".");
        }

        result.append(name.orElse("<anonymous>"))
                .append(":")
                .append(type);

        return result.toString();
    }