/// <summary>
/// Write the fields of a single object, quote strings.
/// </summary>
/// <param name="fields"></param>
/// <param name="writer"></param>
/// <returns></returns>
public override async Task WriteFieldsAsync(IFields fields, TextWriter writer)
{
var line = String.Empty;
var data = fields.GetFields();
for (int i = 0; i < columns.Length; i++)
{
if (i > 0)
{
line += separator;
}
line += QuoteString(data[columns[i]].ToString());
}
await writer.WriteLineAsync(line);
}