As I started with MUMPS, $H was a few days ahead of 50000, this means, I wrote my first programm (MUMPS V4b on a DEC PDP-11/34) even before ISC was founded. I have never made a direct use of those functions but, if a recall it right, they are used during the installation process (database creation, etc.) .  A quick look into the oldest docs I have (Cache 2.3) says nothing about those functions.

kill args
set args($i(args))="arg1"
set args($i(args))="arg2"
set args($i(args))="arg3"
...
set resultSet = ##class(%SQL.Statement).%ExecDirect( , sql_whereClause, args...)

RemoveDirectoryTree(some_dir) works, if it returns FALSE to you so
- either your Ensemble instance has no rights to delete files and directories
- or you feed RemoveDirrectoryTree() with a filename or with a  nonexistent directory

Try the following:

write FileUnZip,! // this should be an existing DIRECTORY
write ##class(%File).Attribute(FileUnZip),! // this should be 16 (on Windows)
write ##class(%File).RemoveDirectoryTree(FileUnZip),! // 1=removed, 0=not-removed

In some way, I wonder about your question. This is a very specific question and a correct and accurate answer can be given by Intersystems only. If you take a look on the articles here, the most of them are about other lanuages, new technologies etc. but none of Cache/IRIS internals. If you look on the questions, very often they start with "I'm new to ISC technologies, need some help". Do you really expect an answer from an newbe? Or you really expect an answer from a Kubernetes, Phyton, Angular etc. developer? On the other hand, you are an Intersystems employee, so why don't ask somebody from the developer department? What about contacting WRC? I would be ashamed to ask such a question here.

My solution, assuming that B is originated from A by some number of left or right rotations

ClassMethod RotationRight(a As %String, b As %String) As %Integer
{
    f i=0:1 ret:$e(a_a,$l(a)+1-i,*-i)=b i
}
    
ClassMethod RotationLeft(a As %String, b As %String) As %Integer
{
    f i=0:1 ret:$e(a_a,i+1,$l(a)+i)=b i
}

write ##class(%Dictionary.MethodDefinition).%OpenId("...||Rotate...").Implementation.Size

gives  40 (for RotateRight) and 38 (for RotateLeft).

I have no idea, from which error you talk.

ClassMethod MyRequest()
{
	set req = ##class(%Net.HttpRequest).%New()
	set req.Server = "msedgewebdriverstorage.blob.core.windows.net"
	set req.SSLConfiguration="Open"
	set req.Https=1
	do req.Get("/edgewebdriver/?comp=list")
	set rsp=req.HttpResponse
	
	if rsp.StatusCode=200 {
		write "Data Size: ",rsp.Data.Size,!
		write "Dumping the first 256 bytes..." zzdump rsp.Data.Read(256)
		
	} else {
		write "Return Code: ",rsp.StatusCode,!
		write "Resp.Phrase: ",rsp.ReasonPhrase,!
	}
	
	quit rsp
}

The output is just fine... no errors.

do ##class(...).MyRequest() --->

Data Size: 1832857
Dumping the first 256 bytes...
0000: EF BB BF 3C 3F 78 6D 6C 20 76 65 72 73 69 6F 6E         <?xml version
0010: 3D 22 31 2E 30 22 20 65 6E 63 6F 64 69 6E 67 3D         ="1.0" encoding=
0020: 22 75 74 66 2D 38 22 3F 3E 3C 45 6E 75 6D 65 72         "utf-8"?><Enumer
0030: 61 74 69 6F 6E 52 65 73 75 6C 74 73 20 43 6F 6E         ationResults Con
0040: 74 61 69 6E 65 72 4E 61 6D 65 3D 22 68 74 74 70         tainerName="http
0050: 73 3A 2F 2F 6D 73 65 64 67 65 77 65 62 64 72 69         s://msedgewebdri
0060: 76 65 72 73 74 6F 72 61 67 65 2E 62 6C 6F 62 2E         verstorage.blob.
0070: 63 6F 72 65 2E 77 69 6E 64 6F 77 73 2E 6E 65 74         core.windows.net
0080: 2F 65 64 67 65 77 65 62 64 72 69 76 65 72 2F 22         /edgewebdriver/"
0090: 3E 3C 42 6C 6F 62 73 3E 3C 42 6C 6F 62 3E 3C 4E         ><Blobs><Blob><N
00A0: 61 6D 65 3E 31 30 30 2E 30 2E 31 31 35 34 2E 30         ame>100.0.1154.0
00B0: 2F 65 64 67 65 64 72 69 76 65 72 5F 61 72 6D 36         /edgedriver_arm6
00C0: 34 2E 7A 69 70 3C 2F 4E 61 6D 65 3E 3C 55 72 6C         4.zip</Name><Url
00D0: 3E 68 74 74 70 73 3A 2F 2F 6D 73 65 64 67 65 77         >https://msedgew
00E0: 65 62 64 72 69 76 65 72 73 74 6F 72 61 67 65 2E         ebdriverstorage.
00F0: 62 6C 6F 62 2E 63 6F 72 65 2E 77 69 6E 64 6F 77         blob.core.window

You have to work with the Data property of the response object (which is a 1.8MB  stream)

COS does not have a pointer operator so instead of "unsigned *rx and *tx" (those are char arrays) in COS you can use string variables. By the way, C counts from 0 to N-1, COS counts from 1 to N, where N ist the size of the character array respectively the length of the string.

Class DC.CtoCOS [ Abstract ]
{

/// Encode a whole string (and return a string)
/// Use the below $ziswide(str) function to check for allowed characters
ClassMethod Encode(str As %String) As %String
{
	f i=$l(str):-1:1 s $e(str,i)=$c($a(str,i)#16+32, $a(str,i)\16+32)
	q str
}

/// Decode a whole string (and return a string)
/// Use the below $match(str,...) function to check for allowed characters
ClassMethod Decode(str As %String) As %String
{
	f i=$l(str):-2:1 s $e(str,i-1,i)=$c($a(str,i)-32*16+$a(str,i-1)-32)
	q str
}

/// Encode a characyter into a string (variable)
/// Use: do ##class(...).Encode1("A", .res)
///      write res --> !$
ClassMethod Encode1(chr As %String, chrs As %String)
{
	i $ziswide(chr) throw ##class(%Exception.General).%New("WIDE",,,chr)
	s chrs=$c($a(chr)#16+32, $a(chr)\16+32)
}

/// Encode an integer (byte value) and return a string
/// Use: write ##class(...).Encode2("A") --> !$
ClassMethod Encode2(val As %Integer) As %String
{
	i val>255 throw ##class(%Exception.General).%New("WIDE",,,val)
	q $c($a(val)#16+32, $a(val)\16+32)
}

/// Decode two characters and return one character
/// Use: write ##class(...).Decode1("!$") --> A
ClassMethod Decode1(chrs As %String) As %String
{
	i $match(chrs,"[ -/]{2}") q $c($a(chrs,2)-32*16+$a(chrs)-32)
	throw ##class(%Exception.General).%New("RANGE",,,chrs)
}

/// Decode two characters and return an integer
/// Use: write ##class(...).Decode2("!$") --> 65
ClassMethod Decode2(chrs As %String) As %Integer
{
	i $match(chrs,"[ -/]{2}") q $a(chrs,2)-32*16+$a(chrs)-32
	throw ##class(%Exception.General).%New("RANGE",,,chrs)
}

}

What does a nervous twitching guitarist has to do with this developer community? I thought, this is a community of professionals and not of script kiddies. It's sorry to say, but under such circumstances I do not want to participate here. Just to make it clear, I have nothing against a video which demonstrates a Cache or IRIS feature, or which is a recording of a webinar or something similar but it should have something in common with development, with the database or at least with the lanuages or tools we use.

Just open the class and see, what it does.
Because the class extends %Projection.AbstractProjection, you could use it in one of your own classes:

Class your.class Extends %Persistent
{
 Projection Test As %Projection.Monitor(MONENABLED=1);
}

But don't ask me, what the class does or should do...

Create an abstract class and add it to all your classes, where a list of properties (for whatever reason) is needed 

Class DC.ClassInfo [ Abstract ]
{

/// Return property info: %PropNames(all)
/// 
/// all: 1 = Return a list of all properties<br>
///      0 = Return a list of storable properties only
ClassMethod PropNames(all = 0) As %String [ CodeMode = objectgenerator ]
{
    s (prop(0),prop(1))=""
    f i=1:1:%compiledclass.Properties.Count() {
        s p=%compiledclass.Properties.GetAt(i), s=p.Storable
        s prop(s)=prop(s)_$e(",",prop(s)]"")_p.Name
    }
    d %code.WriteLine($c(9)_"s stor="""_prop(1)_"""")
    d %code.WriteLine($c(9)_"q $s(all:"""_prop(0)_$e(",",prop(0)]"")_"""_stor,1:stor)")
    q $$$OK
}

}

For example

Class My.Person Extends (%Persistent, DC.ClassInfo)
{
Property Name As %String;
Property Age As %Integer;
}

Putting all together

write ##class(My.Person).PropNames() --> Age,Name
write ##class(My.Person).PropNames(1) --> %%OID,%Concurrency,Age,Name

// That way, in your application, you can easily check,
// if a property exists or not
if $length(##class(My.Person).PropNames(), ",", "TestProp") -->0
if $length(##class(My.Person).PropNames(), ",", "Age") -->1

ClassMethod Pyramide(n)
{
    s a="#" f i=1:1:n w ?n-i,a,! s a=a_"##"
}

Maybe there is a shorter solution, I don't know...