setHeader = function(column, newValue) {
    const obj = this;

    if (obj.headers[column]) {
        const oldValue = obj.headers[column].textContent;
        const onchangeheaderOldValue = (obj.options.columns && obj.options.columns[column] && obj.options.columns[column].title) || '';

        if (! newValue) {
            newValue = getColumnName(column);
        }

        obj.headers[column].textContent = newValue;
        // Keep the title property
        obj.headers[column].setAttribute('title', newValue);
        // Update title
        if (!obj.options.columns) {
            obj.options.columns = [];
        }
        if (!obj.options.columns[column]) {
            obj.options.columns[column] = {};
        }
        obj.options.columns[column].title = newValue;

        setHistory.call(obj, {
            action: 'setHeader',
            column: column,
            oldValue: oldValue,
            newValue: newValue
        });

        // On onchange header
        dispatch.call(obj, 'onchangeheader', obj, parseInt(column), newValue, onchangeheaderOldValue);
    }
}
Set the column title

@param column - column number (first column is: 0)
@param title - new column title