public double?ExtractSpeedFromHtml(string html_document_2)
{
if (html_document_2.Contains("Error - VesselFinder"))
{
return(null);
}
string node = _creator.CreatePrepareAndVerifyRowNodeString(html_document_2);
string speed = _stringParser.GetTrimmedSpeed(node);
return(_stringParser.ParsedTrimmedNullableDouble(speed));
}