old_contents: """
  Support for showing random numbers.
  
  For more details about this platform, please refer to the documentation at
  https://home-assistant.io/components/sensor.random/
  """
  import asyncio
  import logging
  
  import voluptuous as vol
  
  import homeassistant.helpers.config_validation as cv
  from homeassistant.components.sensor import PLATFORM_SCHEMA
  from homeassistant.const import (CONF_NAME, CONF_MINIMUM, CONF_MAXIMUM)
  from homeassistant.helpers.entity import Entity
  
  _LOGGER = logging.getLogger(__name__)
  
  DEFAULT_NAME = 'Random Sensor'
  DEFAULT_MIN = 0
  DEFAULT_MAX = 20
  
  ICON = 'mdi:hanger'
  
  PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
      vol.Optional(CONF_MAXIMUM, default=DEFAULT_MAX): cv.positive_int,
      vol.Optional(CONF_MINIMUM, default=DEFAULT_MIN): cv.positive_int,
      vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
  })
  
  
  @asyncio.coroutine
  def async_setup_platform(hass, config, async_add_devices, discovery_info=None):
      """Setup the Random number sensor."""
      name = config.get(CONF_NAME)
      minimum = config.get(CONF_MINIMUM)
      maximum = config.get(CONF_MAXIMUM)
  
      async_add_devices([RandomSensor(name, minimum, maximum)], True)
      return True
  
  
  class RandomSensor(Entity):
      """Representation of a Random number sensor."""
  
      def __init__(self, name, minimum, maximum):
          """Initialize the sensor."""
          self._name = name
          self._minimum = minimum
          self._maximum = maximum
          self._state = None
  
      @property
      def name(self):
          """Return the name of the device."""
          return self._name
  
      @property
      def state(self):
          """Return the state of the device."""
          return self._state
  
      @property
      def icon(self):
          """Icon to use in the frontend, if any."""
          return ICON
  
      @asyncio.coroutine
      def async_update(self):
          """Get a new number and updates the states."""
          from random import randrange
          self._state = randrange(self._minimum, self._maximum + 1)
  
new_contents: """
  Support for showing random numbers.
  
  For more details about this platform, please refer to the documentation at
  https://home-assistant.io/components/sensor.random/
  """
  import asyncio
  import logging
  
  import voluptuous as vol
  
  import homeassistant.helpers.config_validation as cv
  from homeassistant.components.sensor import PLATFORM_SCHEMA
  from homeassistant.const import (
      CONF_NAME, CONF_MINIMUM, CONF_MAXIMUM, CONF_UNIT_OF_MEASUREMENT)
  from homeassistant.helpers.entity import Entity
  
  _LOGGER = logging.getLogger(__name__)
  
  DEFAULT_NAME = 'Random Sensor'
  DEFAULT_MIN = 0
  DEFAULT_MAX = 20
  
  ICON = 'mdi:hanger'
  
  PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
      vol.Optional(CONF_MAXIMUM, default=DEFAULT_MAX): cv.positive_int,
      vol.Optional(CONF_MINIMUM, default=DEFAULT_MIN): cv.positive_int,
      vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
      vol.Optional(CONF_UNIT_OF_MEASUREMENT): cv.string,
  })
  
  
  @asyncio.coroutine
  def async_setup_platform(hass, config, async_add_devices, discovery_info=None):
      """Setup the Random number sensor."""
      name = config.get(CONF_NAME)
      minimum = config.get(CONF_MINIMUM)
      maximum = config.get(CONF_MAXIMUM)
      unit = config.get(CONF_UNIT_OF_MEASUREMENT)
  
      async_add_devices([RandomSensor(name, minimum, maximum, unit)], True)
      return True
  
  
  class RandomSensor(Entity):
      """Representation of a Random number sensor."""
  
      def __init__(self, name, minimum, maximum, unit_of_measurement):
          """Initialize the sensor."""
          self._name = name
          self._minimum = minimum
          self._maximum = maximum
          self._unit_of_measurement = unit_of_measurement
          self._state = None
  
      @property
      def name(self):
          """Return the name of the device."""
          return self._name
  
      @property
      def state(self):
          """Return the state of the device."""
          return self._state
  
      @property
      def icon(self):
          """Icon to use in the frontend, if any."""
          return ICON
  
      @property
      def unit_of_measurement(self):
          """Return the unit this state is expressed in."""
          return self._unit_of_measurement
  
      @asyncio.coroutine
      def async_update(self):
          """Get a new number and updates the states."""
          from random import randrange
          self._state = randrange(self._minimum, self._maximum + 1)
  
subject: Add optional unit of measurement (#6796)