src/Transient_API.php
public function key( $key = '', $is_option = false ) {
		return $this->get_key( $this->validate_length( $key ), $is_option );
	}
public function key( $key = '', $is_option = false ) {
		return $this->get_key( $this->validate_length( $key ), $is_option );
	}
public function key ( $ key = '' , $ is_option = false ) { return $ this -> get_key ( $ this -> validate_length ( $ key ) , $ is_option ) ; }
Returns a Unique Key.

@param string $key
@param bool   $is_option

@return mixed
Returns a Unique Key .