How to use the spyder.config.manager.CONF function in spyder

dirname = dirname.replace("'", r"\'").replace('"', r'\"')

            runconf = get_run_configuration(fname)
            if runconf is None:
                dialog = RunConfigOneDialog(self)
                dialog.size_change.connect(lambda s: self.set_dialog_size(s))
                if self.dialog_size is not None:
                    dialog.resize(self.dialog_size)
                dialog.setup(fname)
                if CONF.get('run', 'open_at_least_once',
                            not running_under_pytest()):
                    # Open Run Config dialog at least once: the first time
                    # a script is ever run in Spyder, so that the user may
                    # see it at least once and be conscious that it exists
                    show_dlg = True
                    CONF.set('run', 'open_at_least_once', False)
                else:
                    # Open Run Config dialog only
                    # if ALWAYS_OPEN_FIRST_RUN_OPTION option is enabled
                    show_dlg = CONF.get('run', ALWAYS_OPEN_FIRST_RUN_OPTION)
                if show_dlg and not dialog.exec_():
                    return
                runconf = dialog.get_configuration()

            args = runconf.get_arguments()
            python_args = runconf.get_python_arguments()
            interact = runconf.interact
            post_mortem = runconf.post_mortem
            current = runconf.current
            systerm = runconf.systerm
            clear_namespace = runconf.clear_namespace
            console_namespace = runconf.console_namespace

dirname = dirname.replace("'", r"\'").replace('"', r'\"')

            runconf = get_run_configuration(fname)
            if runconf is None:
                dialog = RunConfigOneDialog(self)
                dialog.size_change.connect(lambda s: self.set_dialog_size(s))
                if self.dialog_size is not None:
                    dialog.resize(self.dialog_size)
                dialog.setup(fname)
                if CONF.get('run', 'open_at_least_once',
                            not running_under_pytest()):
                    # Open Run Config dialog at least once: the first time
                    # a script is ever run in Spyder, so that the user may
                    # see it at least once and be conscious that it exists
                    show_dlg = True
                    CONF.set('run', 'open_at_least_once', False)
                else:
                    # Open Run Config dialog only
                    # if ALWAYS_OPEN_FIRST_RUN_OPTION option is enabled
                    show_dlg = CONF.get('run', ALWAYS_OPEN_FIRST_RUN_OPTION)
                if show_dlg and not dialog.exec_():
                    return
                runconf = dialog.get_configuration()

            args = runconf.get_arguments()
            python_args = runconf.get_python_arguments()
            interact = runconf.interact
            post_mortem = runconf.post_mortem
            current = runconf.current
            systerm = runconf.systerm
            clear_namespace = runconf.clear_namespace
            console_namespace = runconf.console_namespace

def save(self):
        CONF.set_shortcut(self.context, self.name, self.key)

def _get_credentials_from_settings(self):
        """Get the stored credentials if any."""
        remember_me = CONF.get('main', 'report_error/remember_me')
        remember_token = CONF.get('main', 'report_error/remember_token')
        username = CONF.get('main', 'report_error/username', '')
        if not remember_me:
            username = ''

        return username, remember_me, remember_token

def update_font(self):
        """Update font from Preferences"""
        font = self.get_font()
        color_scheme = self.get_color_scheme()
        for editorstack in self.editorstacks:
            editorstack.set_default_font(font, color_scheme)
            completion_size = CONF.get('main', 'completion/size')
            for finfo in editorstack.data:
                comp_widget = finfo.editor.completion_widget
                comp_widget.setup_appearance(completion_size, font)

def _load_all_breakpoints():
    return CONF.get('run', 'breakpoints', {})

"""Editor config page."""

from qtpy.QtCore import Qt
from qtpy.QtWidgets import (QGridLayout, QGroupBox, QHBoxLayout, QLabel,
                            QTabWidget, QVBoxLayout, QWidget)

from spyder.api.preferences import PluginConfigPage
from spyder.config.base import _
from spyder.config.manager import CONF
import spyder.utils.icon_manager as ima


NUMPYDOC = "https://numpydoc.readthedocs.io/en/latest/format.html"
GOOGLEDOC = "https://sphinxcontrib-napoleon.readthedocs.io/en/latest/example_google.html"
DOCSTRING_SHORTCUT = CONF.get('shortcuts', 'editor/docstring')


class EditorConfigPage(PluginConfigPage):
    def get_name(self):
        return _("Editor")

    def get_icon(self):
        return ima.icon('edit')

    def setup_page(self):
        newcb = self.create_checkbox

        # --- Display tab ---
        showtabbar_box = newcb(_("Show tab bar"), 'show_tab_bar')
        showclassfuncdropdown_box = newcb(
                _("Show selector for classes and functions"),

add_shortcut_to_tip=True)

        run_selected_action = create_action(self, _("Run &selection or "
                                                    "current line"),
                                            icon=ima.icon('run_selection'),
                                            tip=_("Run selection or "
                                                  "current line"),
                                            triggered=self.run_selection,
                                            context=Qt.WidgetShortcut)
        self.register_shortcut(run_selected_action, context="Editor",
                               name="Run selection", add_shortcut_to_tip=True)

        run_cell_action = create_action(self,
                            _("Run cell"),
                            icon=ima.icon('run_cell'),
                            shortcut=CONF.get_shortcut('editor', 'run cell'),
                            tip=_("Run current cell \n"
                                  "[Use #%% to create cells]"),
                            triggered=self.run_cell,
                            context=Qt.WidgetShortcut)

        run_cell_advance_action = create_action(
            self,
            _("Run cell and advance"),
            icon=ima.icon('run_cell_advance'),
            shortcut=CONF.get_shortcut('editor', 'run cell and advance'),
            tip=_("Run current cell and go to the next one "),
            triggered=self.run_cell_and_advance,
            context=Qt.WidgetShortcut)

        debug_cell_action = create_action(
            self,

def get_color_scheme(name):
    """Get a color scheme from config using its name"""
    name = name.lower()
    scheme = {}
    for key in COLOR_SCHEME_KEYS:
        try:
            scheme[key] = CONF.get('appearance', name+'/'+key)
        except:
            scheme[key] = CONF.get('appearance', 'spyder/'+key)
    return scheme

def save(self):
        if self.language is not None:
            language = self.language.lower()
            CONF.set('lsp-server', language, self.__dict__)