code: def get_main_activity(self):
          
          x = set()
          y = set()
  
          for i in self.xml:
              activities_and_aliases = self.xml[i].getElementsByTagName("activity") + \
                                       self.xml[i].getElementsByTagName("activity-alias")
  
              for item in activities_and_aliases:
                  # Some applications have more than one MAIN activity.
                  # For example: paid and free content
                  activityEnabled = item.getAttributeNS(NS_ANDROID_URI, "enabled")
                  if activityEnabled is not None and activityEnabled != "" and activityEnabled == "false":
                      continue
  
                  for sitem in item.getElementsByTagName("action"):
                      val = sitem.getAttributeNS(NS_ANDROID_URI, "name")
                      if val == "android.intent.action.MAIN":
                          x.add(item.getAttributeNS(NS_ANDROID_URI, "name"))
  
                  for sitem in item.getElementsByTagName("category"):
                      val = sitem.getAttributeNS(NS_ANDROID_URI, "name")
                      if val == "android.intent.category.LAUNCHER":
                          y.add(item.getAttributeNS(NS_ANDROID_URI, "name"))
  
          z = x.intersection(y)
          if len(z) > 0:
              return self.format_value(z.pop())
          return None
docs: Return the name of the main activity
  
              :rtype: string