Mem leak PySide2 - heavy window creation + disposal

import gc
import logging
import os

import psutil
from PySide2 import QtWidgets, QtCore


def create_timer():
    timer = QtCore.QTimer(qApp)
    timer.setSingleShot(True)
    timer.setInterval(10)
    timer.start()
    return timer


logging.basicConfig()
L = logging.getLogger()
L.setLevel(1)
qApp = QtWidgets.QApplication(os.sys.argv)
TIMER = create_timer()
WINDOW = QtWidgets.QPushButton("Quit me!")
WINDOW.clicked.connect(qApp.quit)
WINDOW.show()
COUNTER = 0
ACTUAL_WINDOW = None


class ManagedSubWindow(QtWidgets.QWidget):
    """Class fixing the multiple concurrent window problem.
    It "remembers" on the class level all its children, until they are to be
    destroyed."""
    active_sub_windows = set()  # register of still active windows - prevention

    # against garbage collecting and SigSeg (11) signal = exitcode 139

    def __init__(self, *args, **kwargs):
        """Register the window on its creation"""
        kwargs["parent"] = WINDOW
        super().__init__(*args, **kwargs)
        self.setWindowFlags(QtCore.Qt.Window |
                            QtCore.Qt.WindowMinimizeButtonHint |
                            QtCore.Qt.WindowMaximizeButtonHint |
                            QtCore.Qt.WindowCloseButtonHint)
        self.active_sub_windows.add(self)
        self.internals = kwargs.get("internals")

    def closeEvent(self, ce):
        """Un-register the window + delete what is inside"""
        # L.debug("ManagedSubWindow.closeEvent received %s", ce)
        if self not in self.active_sub_windows:
            L.debug("This window was yet closed... strange.")
        self.active_sub_windows.discard(self)
        del self.internals
        self.setParent(None)
        ce.accept()
        self.deleteLater()
        ret_value = super().closeEvent(ce)
        self.destroy(destroyWindow=True, destroySubWindows=True)
        return ret_value


def create_window():
    """Create a subwindow"""
    global COUNTER
    global ACTUAL_WINDOW
    global TIMER
    COUNTER += 1
    if not (COUNTER % 100):
        gc.collect()
        process = psutil.Process(os.getpid())
        used_ram = process.memory_info().rss
        used_ram /= 2. ** 20
        L.debug("active_sub_windows count %s ; used_ram %s",
                len(ManagedSubWindow.active_sub_windows), used_ram)
    ACTUAL_WINDOW = ManagedSubWindow()
    ACTUAL_WINDOW.show()
    TIMER = create_timer()
    TIMER.timeout.connect(close_window)


def close_window():
    """Close a subwindow"""
    global ACTUAL_WINDOW
    global TIMER
    ACTUAL_WINDOW.close()
    TIMER = create_timer()
    TIMER.timeout.connect(create_window)


TIMER.timeout.connect(create_window)
os.sys.exit(qApp.exec_())