WordPress/Sniffs/WP/DeprecatedFunctionsSniff.php
public function getGroups() {
		// Make sure all array keys are lowercase.
		$this->deprecated_functions = array_change_key_case( $this->deprecated_functions, CASE_LOWER );

		return array(
			'deprecated_functions' => array(
				'functions' => array_keys( $this->deprecated_functions ),
			),
		);
	}
public function getGroups() {
		// Make sure all array keys are lowercase.
		$this->deprecated_functions = array_change_key_case( $this->deprecated_functions, CASE_LOWER );

		return array(
			'deprecated_functions' => array(
				'functions' => array_keys( $this->deprecated_functions ),
			),
		);
	}
Groups of functions to restrict.

@return array