source/php/Entity/CustomPostType.php
public function tableColumns($columns)
    {
        if (!empty($this->tableColumns) && is_array($this->tableColumns)) {
            $columns = $this->tableColumns;
        }

        return $columns;
    }
public function tableColumns($columns)
    {
        if (!empty($this->tableColumns) && is_array($this->tableColumns)) {
            $columns = $this->tableColumns;
        }

        return $columns;
    }
Set up table columns
@param  array $columns Default columns
@return array          New columns