Take a look at Creating and Using Terminal Scripts

It seems to me that there is a typo in the TestStartBottomLeft method:

should be  Do $$$AssertEquals(##class(codeGolf.ClockwiseWord).Solution(.matrix, 3, 1), "781234569")

I'm not familiar with Ensemble, but it may be possible to replace the regular stream with the %Stream.GlobalCharacterSearchable class?

Please note the following warning:

Important:

There are known incompatibilities between InterSystems IRIS and Python 3.13, so you are advised to avoid Python 3.13 at this time. This issue will be addressed in an upcoming version of InterSystems IRIS.

That's right, the generated code lacks $GET or initial initialization of the variable.

Yes, these are fields that will either be inserted or updated.

PS:
In fact, the following query should work correctly:

INSERT OR UPDATE myTable SET name='Omer',  counter = NVL(counter,0) + 1 

But unfortunately, the SQL engine generates code where an undefined variable is accessed, so the <UNDEFINED> error occurs.
Try contacting WRC for a fix.

By the way, in SQL Data Lens, which works via JDBC, it is possible to see the source code of classes:

https://sqldatalens.com/class-viewer/

Class dc.test [ Abstract ]
{

ClassMethod Stream2BytesArray1(stream As %Stream.Object) As %SYS.Python [ Language = python ]
{
  stream.Rewind()
  s = ""
  while not stream.AtEnd:
    r = stream.Read(1000000)
    s += r
  b = bytearray()
  b.extend(map(ord, s))
  return b
}

ClassMethod Stream2BytesArray2(stream As %Stream.Object) As %SYS.Python [ Language = python ]
{
  import iris

  maxlen = iris.system.SYS.MaxLocalLength()
  b = bytearray()

  stream.Rewind()
  while not stream.AtEnd:
    b.extend(iris._SYS.Python.Bytes(stream.Read(maxlen)))
  return b
}

ClassMethod Stream2BytesArray3(stream As %Stream.Object) As %SYS.Python
{
  set maxlen = $$$MaxLocalLength,
      b = $SYSTEM.Python.Builtins().bytearray()

  do stream.Rewind()
  while 'stream.AtEnd {do b.extend($system.Python.Bytes(stream.Read(maxlen)))}
  return b
}

/// d ##class(dc.test).Test()
ClassMethod Test()
{
  s builtin=$system.Python.Builtins(),
    maxstr=$tr($j("",$$$MaxStringLength)," ","0"),
    stream=##class(%GlobalBinaryStream).%New()
  f i=1:1:7 d stream.Write(maxstr)
  w "Stream.Size=",stream.Size,!
  
  f n=1:1:3 {
    s fn="Stream2BytesArray"_n,t=$zh,r=$CLASSMETHOD($this,fn,stream),t=($zh-t)_" s."
    w $$$FormatText("%1 len(r)=%2 time=%3",fn,builtin.len(r),t),!
  }
}

}

USER>d ##class(dc.test).Test()
Stream.Size=25488008
Stream2BytesArray1 len(r)=25488008 time=.752708 s.
Stream2BytesArray2 len(r)=25488008 time=.14895 s.
Stream2BytesArray3 len(r)=25488008 time=.080003 s.

The numbers speak for themselves.

ClassMethod Stream2BytesArray(stream As %Stream.Object) As %SYS.Python
{
  set builtin = $SYSTEM.Python.Builtins()

  set b = builtin.bytearray()

  do stream.Rewind()
  while 'stream.AtEnd {
    set r = $system.Python.Bytes(stream.Read($$$MaxLocalLength))
    do b.extend(r)
  }
  quit b
}

Here you can find version 3.10.2:

https://repo.maven.apache.org/maven2/com/intersystems/intersystems-jdbc/

• Parallel Query Processing Ignored
• Parallel Query Processing for a Specific Query

And don't forget about AutoParallelThreshold

It seems to me that in this case it would be advisable to use a comparison of stream hashes, using, for example, the SHA3HashStream method.