old_contents: ## The core sensor class
  #
  # This class is used as the base for all sensors and defines a common interface.
  
  def mergeOptions(defaults, options):
      """Returns a dictionary where options are merged into the defaults""" 
      merged_options = defaults.copy()
      for key, val in options.iteritems():
          if key in merged_options:
              merged_options[key] = val
      return merged_options
          
      
  
  DEFAULT_OPTIONS = {
      'interval': 0,
      'unit': "s"
  }
  
  
  class GeneralSensor(object):
      """A general super class used to define the interface for a sensor"""
      
      def __init__(self, options={}):
          self.active = True
          self.options = mergeOptions(DEFAULT_OPTIONS, options)
      
      def setupSensor(self):
          pass
      
      def getValue(self):
          """Returns the current value of the sensor"""
          pass
          
      def activate(self):
          """If implemented, wakes sensor form a sleap mode in order to take a reading"""
          self.active = True
      
      def deactivate(self):
          """If implemented, puts sensor to sleap in order to save power"""
          self.active = False
          
      def getOptionValue(self, option):
          """Returns the value of the option"""
          return self.options[option]
      
      def setOptionValue(self, option, value):
          """Sets the value for the option"""
          self.options[option] = value
          
          
new_contents: ## The core sensor class
  #
  # This class is used as the base for all sensors and defines a common interface.
  
  def mergeOptions(defaults, options):
      """Returns a dictionary where options are merged into the defaults""" 
      merged_options = defaults.copy()
      for key, val in options.iteritems():
          if key in merged_options:
              merged_options[key] = val
      return merged_options
          
      
  
  DEFAULT_OPTIONS = {
      'interval': 0,
      'unit': "s"
  }
  
  
  class GeneralSensor(object):
      """A general super class used to define the interface for a sensor"""
      
      def __init__(self, options={}):
          self.active = True
          self.options = mergeOptions(DEFAULT_OPTIONS, options)
      
      def setupSensor(self):
          pass
      
      def getValue(self):
          """Returns the current value of the sensor"""
          pass
          
      def activate(self):
          """If implemented, wakes sensor form a sleap mode in order to take a reading"""
          self.active = True
      
      def deactivate(self):
          """If implemented, puts sensor to sleap in order to save power"""
          self.active = False
          
      def getOptionValue(self, option):
          """Returns the value of the option"""
          return self.options[option]
      
      def setOptionValue(self, option, value):
          """Sets the value for the option"""
          self.options[option] = value
  
  class HardwareSensor(object):
      """Lowlevel class used to interface with a hardware sensor"""
      
      def __init__(self, options={}):
          self.active = True
          self.options = mergeOptions(DEFAULT_OPTIONS, options)
      
          
subject: add core sensor