The documentation for column_class() in tablelib.php is incorrect:

/**

• Sets the given $column index to the given $classname in $this->column_class.
• @param int $column
• @param string $classname
• @return void
  */

However if you pass an integer value to it, nothing happens.

Further review of the code and by dumping out the $this->column_class variable shows that $this->column_class is actually an associative array of column names.

The documentation in the class should be:

/**

• Sets the column named $columnname  to the given $classname in $this->column_class.
• @param string $columnname
• @param string $classname
• @return void
  */

This may apply to other column_* functions in table lib.