Tests/RunCMake/separate_arguments/EmptyCommand.cmake - third_party/github.com/Kitware/CMake - Git at Google

 set(nothing)
 separate_arguments(nothing)
 if(DEFINED nothing)
   message(FATAL_ERROR "separate_arguments null-case failed: "
     "nothing=[${nothing}]")
 endif()
	set(nothing)
	separate_arguments(nothing)
	if(DEFINED nothing)
	message(FATAL_ERROR "separate_arguments null-case failed: "
	"nothing=[${nothing}]")
	endif()