anchor.diff:  	Name = {"name", "HTTPTransferUsageSpec"},
   	Desc = {"description", "Specification for SigScale OCS http requests."},
   	Start = {"startDateTime", "2017-01-01T00:00:00Z"},
  -	End = {"endDateTime", "2017-12-31T23:59:59Z"},
  +	End = {"endDateTime", undefined},
   	Valid = {"validFor", {struct, [Start, End]}},
   	Chars = [{struct, [{"todo", "todo"}]}],
   	Char = {"usageSpecCharacteristic", {array, Chars}},
  
positive.code: 	Name = {"name", "AAAAccessUsageSpec"},
  	Desc = {"description", "Specification for SigScale OCS access requests."},
  	Start = {"startDateTime", "2017-01-01T00:00:00Z"},
  	End = {"endDateTime", "2017-12-31T23:59:59Z"},
  	Valid = {"validFor", {struct, [Start, End]}},
  	Chars = [spec_protocol(), spec_node(), spec_server_address(),
  			spec_server_port(), spec_client_address(),
  
negative.code: 	Name = {"name", "VoIPUsageSpec"},
  	Desc = {"description", ""},
  	Start = {"startDateTime", "2018-03-12T00:00:00Z"},
  	End = {"endDateTime", undefined},
  	Valid = {"validFor", {struct, [Start, End]}},
  	Chars = lists:reverse(spec_voip1([])),
  	Char = {"usageSpecCharacteristic", {array, Chars}},
  