Does D have an equivalent to C#'s String.IsNullOrWhiteSpace?

[Nieto via Digitalmars-d-learn]

Does D have an equivalent to C#'s String.IsNullOrWhiteSpace() in 
the standard library?
just asking if there's a native one, so I don't need reinvente 
the wheel

https://msdn.microsoft.com/en-us/library/system.string.isnullorwhitespace%28v=vs.110%29.aspx?f=255&MSPPError=-2147217396