code: private function getClosure($parameter)
      {
          $closure = null;
  
          foreach (array_keys($this->parameterCluster->prefixes) as $prefix) {
              if (substr($parameter, 0, strlen($prefix)) == $prefix) {
                  @$closure = $this->parameterCluster->prefixes[$prefix][
                      substr(
                          $parameter,
                          strlen($prefix),
                          strlen($parameter) - strlen($prefix)
                      )
                  ]->parameterClosure;
              }
          }
  
          return $closure;
      }
docs: Attempts to find the closure associated with the parameter
  based on prefix. If no prefix is found, null will be returned.
  
  @param string $parameter
  
  @return Closure