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

[Adam D. Ruppe]

On Thursday, 12 October 2017 at 18:11:55 UTC, Nieto wrote:
> Does D have an equivalent to C#'s String.IsNullOrWhiteSpace() 
> in the standard library?

import std.string;

if(str.strip().length == 0) {
   // is null, empty, or all whitespace
}