use crate;
/// Represents a reusable SQL fragment node in py_sql, defined by a `<sql>` tag in XML or an equivalent in py_sql.
/// It allows defining a piece of SQL that can be included elsewhere.
///
/// # Example
///
/// PySQL syntax (conceptual, as direct py_sql for `<sql>` might be less common than XML):
/// ```py
/// # define a reusable sql fragment
/// sql id='columns':
/// column1, column2
/// ```