code: private function getValueFromSource($source, $valueName, $arguments)
      {
          switch (strtolower($source)) {
              case 'get':
                  return $this->container->get(Input::class)->get($valueName);
  
              case 'post':
                  return $this->container->get(Input::class)->post($valueName);
  
              case 'cookie':
                  return $this->container->get(Input::class)->cookie($valueName);
  
              case 'session':
                  return $this->container->get(Session::class)->get($valueName);
  
              case 'filter':
                  if (is_array($this->filterParameters)) {
                      if (array_key_exists($valueName, $this->filterParameters)) {
                          return $this->filterParameters[$valueName];
                      }
  
                      return null;
                  }
                  break;
  
              case 'container':
                  // @codingStandardsIgnoreStart
                  @trigger_error(
                      'Getting filter values from the service container is deprecated, the container will get removed.',
                      E_USER_DEPRECATED
                  );
                  // @codingStandardsIgnoreEnd
                  return $this->getValueFromServiceContainer($valueName, $arguments);
  
              default:
          }
  
          // Unknown sources always resort to null.
          return null;
      }
docs: Retrieve the value with the given name from the source with the given name.
  
  @param string $source    The source to retrieve the value from.
  Valid values are: ('get', 'post', 'cookie', 'session', 'filter' or 'container').
  
  @param string $valueName The name of the value in the source to retrieve.
  
  @param array  $arguments The arguments of the parameter.
  
  @return mixed