/**
  * Registers the plugin meta boxes
  * 
  * @since            2.0.3
  */
 private function _registerMetaBoxes()
 {
     $GLOBALS['strAmazonAutoLinks_UnitType'] = AmazonAutoLinks_Option::getUnitType();
     $_sUnitType = $GLOBALS['strAmazonAutoLinks_UnitType'];
     $_bIsUpdatingUnit = empty($_GET) && 'post.php' === $GLOBALS['pagenow'];
     // when saving the meta data, the GET array is empty
     if ($_sUnitType == 'category' || $_bIsUpdatingUnit) {
         new AmazonAutoLinks_MetaBox_CategoryOptions('amazon_auto_links_category_unit_options_meta_box', __('Category Unit Options', 'amazon-auto-links'), array(AmazonAutoLinks_Commons::PostTypeSlug), 'normal', 'default');
         new AmazonAutoLinks_MetaBox_Categories();
     }
     // Do not use  else here for the meta box saving process
     if ($_sUnitType == 'tag' || $_bIsUpdatingUnit) {
         new AmazonAutoLinks_MetaBox_TagOptions('amazon_auto_links_tag_unit_options_meta_box', __('Tag Unit Options', 'amazon-auto-links'), array(AmazonAutoLinks_Commons::PostTypeSlug), 'normal', 'default');
     }
     // Do not use  else here for the meta box saving process
     if ($_sUnitType == 'search' || $_bIsUpdatingUnit) {
         new AmazonAutoLinks_MetaBox_SearchOptions('amazon_auto_links_search_unit_options_meta_box', __('Search Unit Options', 'amazon-auto-links'), array(AmazonAutoLinks_Commons::PostTypeSlug), 'normal', 'default');
         new AmazonAutoLinks_MetaBox_SearchOptions_Advanced('amazon_auto_links_advanced_search_unit_options_meta_box', __('Advanced Search Options', 'amazon-auto-links'), array(AmazonAutoLinks_Commons::PostTypeSlug), 'normal', 'default');
     }
     // Do not use else here for the meta box saving process
     if ($_sUnitType == 'item_lookup' || $_bIsUpdatingUnit) {
         // the second condition is for when updating the unit.
         new AmazonAutoLinks_MetaBox_ItemLookupOptions('amazon_auto_links_item_lookup_unit_options_meta_box', __('Item Look-up Options', 'amazon-auto-links'), array(AmazonAutoLinks_Commons::PostTypeSlug), 'normal', 'default');
         new AmazonAutoLinks_MetaBox_ItemLookupOptions_Advanced('amazon_auto_links_advanced_item_lookup_unit_options_meta_box', __('Advanced Item Look-up Options', 'amazon-auto-links'), array(AmazonAutoLinks_Commons::PostTypeSlug), 'normal', 'default');
     }
     // Do not use else here for the meta box saving process
     if ($_sUnitType == 'similarity_lookup' || $_bIsUpdatingUnit) {
         // the second condition is for when updating the unit.
         new AmazonAutoLinks_MetaBox_SimilarityLookupOptions('amazon_auto_links_similarity_lookup_unit_options_meta_box', __('Similarity Look-up Options', 'amazon-auto-links'), array(AmazonAutoLinks_Commons::PostTypeSlug), 'normal', 'default');
         new AmazonAutoLinks_MetaBox_SimilarityLookupOptions_Advanced('amazon_auto_links_advanced_similarity_lookup_unit_options_meta_box', __('Advanced Similarity Look-up Options', 'amazon-auto-links'), array(AmazonAutoLinks_Commons::PostTypeSlug), 'normal', 'default');
     }
     new AmazonAutoLinks_MetaBox_Template('amazon_auto_links_template_meta_box', __('Template', 'amazon-auto-links'), array(AmazonAutoLinks_Commons::PostTypeSlug), 'normal', 'default');
     new AmazonAutoLinks_MetaBox_Misc();
 }