Function normalize_query 

pub fn normalize_query(query: &str) -> String

Normalize a query string into a stable cache key: trim surrounding whitespace and collapse horizontal whitespace runs into a single space.

Content inside single-quoted strings, double-quoted strings, and backtick-quoted identifiers is preserved verbatim, and newlines are kept, so normalization never changes a query’s semantics (e.g. inside string literals or line comments).