code: public function addPackage($source, $target, $reason)
      {
          $this->suggestedPackages[] = array(
              'source' => $source,
              'target' => $target,
              'reason' => $reason,
          );
  
          return $this;
      }
docs: Add suggested packages to be listed after install
  
  Could be used to add suggested packages both from the installer
  or from CreateProjectCommand.
  
  @param  string                    $source Source package which made the suggestion
  @param  string                    $target Target package to be suggested
  @param  string                    $reason Reason the target package to be suggested
  @return SuggestedPackagesReporter