code: protected function buildBoostFactorMap(array $config)
      {
          $boostFactorMap = [];
  
          foreach ($config['content_type'] as $typeIdentifier => $factor) {
              $boostFactorMap['content-fields'][$typeIdentifier]['*'] = $factor;
              $boostFactorMap['meta-fields'][$typeIdentifier]['*'] = $factor;
          }
  
          foreach ($config['field_definition'] as $typeIdentifier => $mapping) {
              foreach ($mapping as $fieldIdentifier => $factor) {
                  $boostFactorMap['content-fields'][$typeIdentifier][$fieldIdentifier] = $factor;
              }
          }
  
          foreach ($config['meta_field'] as $typeIdentifier => $mapping) {
              foreach ($mapping as $fieldIdentifier => $factor) {
                  $boostFactorMap['meta-fields'][$typeIdentifier][$fieldIdentifier] = $factor;
              }
          }
  
          return $boostFactorMap;
      }
docs: Builds boost factor map from the given $config.
  
  @see \EzSystems\EzPlatformSolrSearchEngine\FieldMapper\BoostFactorProvider::$map
  
  @param array $config
  
  @return array