/**
  * Get the css value for a column
  * @param array $size - The size numbers
  * @example $size   =>  [
  *      0   =>  3   //this value used for extra small devices
  *      1   =>  3   //this value used for small devices
  *      2   =>  4   //this value used for medium devices
  *      3   =>  4   //this value used for large devices
  * ]
  * @param array $offset - with offset numbers
  * @return string - The column css
  */
 public function getColumnClasses($size, $offset = [])
 {
     $class = '';
     if (isset($size[0]) && !empty($size[0])) {
         $class = GeneralFunctions::appendValue($class, BootstrapClasses::COL_XS . $size[0]);
     }
     if (isset($size[1]) && !empty($size[1])) {
         $class = GeneralFunctions::appendValue($class, BootstrapClasses::COL_SM . $size[1]);
     }
     if (isset($size[2]) && !empty($size[2])) {
         $class = GeneralFunctions::appendValue($class, BootstrapClasses::COL_MD . $size[2]);
     }
     if (isset($size[3]) && !empty($size[3])) {
         $class = GeneralFunctions::appendValue($class, BootstrapClasses::COL_LG . $size[3]);
     }
     if (isset($offset[0]) && !empty($offset[0])) {
         $class = GeneralFunctions::appendValue($class, BootstrapClasses::COL_XS_OFFSET . $offset[0]);
     }
     if (isset($offset[1]) && !empty($offset[1])) {
         $class = GeneralFunctions::appendValue($class, BootstrapClasses::COL_SM_OFFSET . $offset[1]);
     }
     if (isset($offset[2]) && !empty($offset[2])) {
         $class = GeneralFunctions::appendValue($class, BootstrapClasses::COL_MD_OFFSET . $offset[2]);
     }
     if (isset($offset[3]) && !empty($offset[3])) {
         $class = GeneralFunctions::appendValue($class, BootstrapClasses::COL_LG_OFFSET . $offset[3]);
     }
     return $class;
 }
 /**
  * Append a value to key array
  * @param array $tbl - The source array
  * @param mixed $key - The key where the value will be appended
  * @param string $value - The value to append
  * @return string
  */
 public static function combineValues($tbl, $key, $value)
 {
     $result = $value;
     if (isset($tbl[$key])) {
         $result = GeneralFunctions::appendValue($tbl[$key], $value);
     }
     return $result;
 }
 /**
  * Get a ul list styled as tabs
  * @param array $items - List items, see getMenuListItems for structure
  * @param $isJustified - true to apply justified css
  * @return <ul class="nav nav-tabs">
  */
 public function getTabs($items, $isJustified = false)
 {
     $class = BootstrapClasses::NAV_TABS;
     if ($isJustified) {
         $class = GeneralFunctions::appendValue($class, BootstrapClasses::NAV_JUSTIFIED);
     }
     return $this->getMenu($class, $items);
 }