Android Code Snippet SaveAs - Let the user select a target folder + list of other related methods

Sub SaveAs (Source As InputStream, MimeType As String, Title As String) As ResumableSub
    Dim intent As Intent
    intent.Initialize("android.intent.action.CREATE_DOCUMENT", "")
    intent.AddCategory("android.intent.category.OPENABLE")
    intent.PutExtra("android.intent.extra.TITLE", Title)
    intent.SetType(MimeType)
    StartActivityForResult(intent)
    Wait For ion_Event (MethodName As String, Args() As Object)
    If -1 = Args(0) Then 'resultCode = RESULT_OK
        Dim result As Intent = Args(1)
        Dim jo As JavaObject = result
        Dim ctxt As JavaObject
        Dim ContentResolver As JavaObject = ctxt.InitializeContext.RunMethodJO("getContentResolver", Null)
        Dim out As OutputStream = ContentResolver.RunMethod("openOutputStream", Array(jo.RunMethod("getData", Null), "wt")) 'wt = Write+Trim
        File.Copy2(Source, out)
        out.Close
        Return True
    End If
    Return False
End Sub

Sub StartActivityForResult(i As Intent)
    Dim jo As JavaObject = GetBA
    ion = jo.CreateEvent("anywheresoftware.b4a.IOnActivityResult", "ion", Null)
    jo.RunMethod("startActivityForResult", Array(ion, i))
End Sub

Sub GetBA As Object
    Dim jo As JavaObject = Me
    Return jo.RunMethod("getBA", Null)
End Sub

Private Sub Button1_Click
    File.WriteString(File.DirInternal, "test.txt", "test") 'just for the example.
    Wait For (SaveAs(File.OpenInput(File.DirInternal, "test.txt"), "application/octet-stream", "test.txt")) Complete (Success As Boolean)
    Log("File saved successfully? " & Success)
End Sub

Sub GetBA As Object
   Dim jo As JavaObject
   Dim cls As String = Me
   cls = cls.SubString("class ".Length)
   jo.InitializeStatic(cls)
   Return jo.GetField("processBA")
End Sub