Please follow:
In addition to PSR-12, Apache Thrift's PHP code does not use leading or trailing underscores on identifiers (properties, methods, constants). Earlier versions of the library carried a Google-C++-style trailing underscore convention on private/protected members; this is no longer accepted. Use plain camelCase for properties and methods, with PHP visibility keywords (private, protected, public) to convey intent.
The phpcs configuration in phpcs.xml.dist enforces PSR-12 across lib/php/lib/ and lib/php/test/.