How to use the octoprint.plugin.SettingsPlugin function in OctoPrint

# defining your plugin as a template plugin, settings and asset plugin. Feel free to add or remove mixins
# as necessary.
#
# Take a look at the documentation on what other plugin mixins are available.

import datetime
import numpy as np
import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
import matplotlib.image as mpimg
import re
import octoprint.plugin
import octoprint.printer

class PrusameshmapPlugin(octoprint.plugin.SettingsPlugin,
                         octoprint.plugin.AssetPlugin,
                         octoprint.plugin.TemplatePlugin,
                         octoprint.plugin.StartupPlugin,
                         octoprint.plugin.EventHandlerPlugin):

	##~~ SettingsPlugin mixin

	def get_settings_defaults(self):
		return dict(
                        do_level_gcode = 'G28 W ; home all without mesh bed level\nG80 ; mesh bed leveling\nG81 ; check mesh leveling results',
                        matplotlib_heatmap_theme = 'viridis'
		)

	##~~ AssetPlugin mixin

	def get_assets(self):

# coding=utf-8
from __future__ import absolute_import

import octoprint.plugin

class youtubelive(octoprint.plugin.StartupPlugin,
				octoprint.plugin.TemplatePlugin,
				octoprint.plugin.AssetPlugin,
                octoprint.plugin.SettingsPlugin):
	
	##~~ StartupPlugin
	def on_after_startup(self):
		self._logger.info("OctoPrint-YouTubeLive loaded!")
	
	##~~ TemplatePlugin
	def get_template_configs(self):
		return [dict(type="settings",custom_bindings=True)]
		
	##~~ AssetPlugin
	def get_assets(self):
		return dict(
			js=["js/youtubelive.js"],
			css=["css/youtubelive.css"]
		)

def on_settings_save(self, data):
        octoprint.plugin.SettingsPlugin.on_settings_save(self, data)
        self.initialize()

from octoprint_PrintJobHistory.models.FilamentModel import FilamentModel
from octoprint_PrintJobHistory.models.PrintJobModel import PrintJobModel
from octoprint_PrintJobHistory.models.TemperatureModel import TemperatureModel
from peewee import DoesNotExist

from .common.SettingsKeys import SettingsKeys
from .api.PrintJobHistoryAPI import PrintJobHistoryAPI
from .api import TransformPrintJob2JSON
from .DatabaseManager import DatabaseManager
from .CameraManager import CameraManager


class PrintJobHistoryPlugin(
							PrintJobHistoryAPI,
							octoprint.plugin.SettingsPlugin,
                            octoprint.plugin.AssetPlugin,
                            octoprint.plugin.TemplatePlugin,
							octoprint.plugin.StartupPlugin,
							octoprint.plugin.EventHandlerPlugin,
							#octoprint.plugin.SimpleApiPlugin
							):


	def initialize(self):
		self._preHeatPluginImplementation = None
		self._preHeatPluginImplementationState = None
		self._filamentManagerPluginImplementation = None
		self._filamentManagerPluginImplementationState = None
		self._displayLayerProgressPluginImplementation = None
		self._displayLayerProgressPluginImplementationState = None
		self._ultimakerFormatPluginImplementation = None

import octoprint.server.util.flask
from octoprint.server import admin_permission, NO_CONTENT
from octoprint.events import Events

# import the flash methods
from octoprint_firmwareupdater.methods import avrdude
from octoprint_firmwareupdater.methods import bossac
from octoprint_firmwareupdater.methods import dfuprog
from octoprint_firmwareupdater.methods import lpc1768
from octoprint_firmwareupdater.methods import stm32flash

class FirmwareupdaterPlugin(octoprint.plugin.BlueprintPlugin,
                            octoprint.plugin.TemplatePlugin,
                            octoprint.plugin.AssetPlugin,
                            octoprint.plugin.SettingsPlugin,
							octoprint.plugin.EventHandlerPlugin):

	def __init__(self):
		self._flash_thread = None

		self._flash_prechecks = dict()
		self._flash_methods = dict()

		self._console_logger = None

	def initialize(self):
		# TODO: make method configurable via new plugin hook "octoprint.plugin.firmwareupdater.flash_methods",
		# also include prechecks
		self._flash_prechecks = dict(avrdude=avrdude._check_avrdude, bossac=bossac._check_bossac, dfuprogrammer=dfuprog._check_dfuprog, lpc1768=lpc1768._check_lpc1768, stm32flash=stm32flash._check_stm32flash)
		self._flash_methods = dict(avrdude=avrdude._flash_avrdude, bossac=bossac._flash_bossac, dfuprogrammer=dfuprog._flash_dfuprog, lpc1768=lpc1768._flash_lpc1768, stm32flash=stm32flash._flash_stm32flash)

def on_settings_save(self, data):
		# make sure we don't get negative values
		for k in ('bed', 'bed_low', 'hotend', 'hotend_low', 'read_timeout', 'interval'):
			if data.get(k): data[k] = max(0, int(data[k]))
		self._logger.debug(u"TemperatureFailsafe on_settings_save(%r)" % (data,))

		octoprint.plugin.SettingsPlugin.on_settings_save(self, data)
		self._restartTimer()