private function extractDocBlockPartsWrapper(): void
  {
    // Get the DocBlock parts from the source of the stored routine.
    $this->extractDocBlockPartsSource();

    // Generate the parameters parts of the DocBlock to be used by the wrapper.
    $parameters = [];
    foreach ($this->parameters as $parameter_info)
    {
      $parameters[] = ['parameter_name'       => $parameter_info['parameter_name'],
                       'php_type'             => DataTypeHelper::columnTypeToPhpTypeHinting($parameter_info).'|null',
                       'data_type_descriptor' => $parameter_info['data_type_descriptor'],
                       'description'          => $this->getParameterDocDescription($parameter_info['parameter_name'])];
    }

    // Compose all the DocBlock parts to be used by the wrapper generator.
    $this->docBlockPartsWrapper = ['sort_description' => $this->docBlockPartsSource['sort_description'],
                                   'long_description' => $this->docBlockPartsSource['long_description'],
                                   'parameters'       => $parameters];
  }