pluckValue method
Extract a single value from the map, returning a GenericBuilder for further operations. @return A GenericBuilder for the extracted value
Implementation
GenericBuilder<dynamic> pluckValue(String key) {
// Pivot value early so subsequent coercions (e.g., toIntStrict) see the plucked scalar.
// Also add a containsKey guard in pre-validators for clearer error when missing.
add(esk.containsKey(key));
chain.addPrefix((child) => tr.pluckKey(key, child));
return GenericBuilder<dynamic>(chain: chain);
}