code: public function mapBoolean($value)
      {
  
          // try to map the passed value to a boolean
          if (isset($this->booleanMapping[$value])) {
              return $this->booleanMapping[$value];
          }
  
          // throw an exception if we can't convert the passed value
          throw new \Exception(sprintf('Can\'t convert %s to boolean', $value));
      }
docs: Map's the passed value to a boolean.
  
  @param string $value The value to map
  
  @return boolean The mapped value
  @throws \Exception Is thrown, if the value can't be mapped