code: public static String getDocumentKey(String type, String mimeType) {
  
          StringBuffer result = new StringBuffer(16);
          result.append(I_CmsSearchDocument.VFS_DOCUMENT_KEY_PREFIX);
          result.append('_');
          result.append(type);
          if (mimeType != null) {
              result.append(':');
              result.append(mimeType);
          }
          return result.toString();
      }
docs: Creates a document factory lookup key for the given resource type name / MIME type configuration.<p>
  
  If the given <code>mimeType</code> is <code>null</code>, this indicates that the key should
  match all VFS resource of the given resource type regardless of the MIME type.<p>
  
  @param type the resource type name to use
  @param mimeType the MIME type to use
  
  @return a document factory lookup key for the given resource id / MIME type configuration