docs: def _applicationStart(self, data):
          """
          Initializes the database connection pool.
  
          :param data: <object> event data object
          :return: <void>
          """
          checkup = False
          if "viper.mysql" in self.application.config \
                  and isinstance(self.application.config["viper.mysql"], dict):
              if "host" in self.application.config["viper.mysql"] and \
                      "port" in self.application.config["viper.mysql"] and \
                      "name" in self.application.config["viper.mysql"]:
                  if len(self.application.config["viper.mysql"]["host"]) > 0 and \
                          self.application.config["viper.mysql"]["port"] > 0 and \
                          len(self.application.config["viper.mysql"]["name"]) > 0:
                      checkup = True
  
          if checkup is not True:
              return
  
          try:
              self._connectionPool = adbapi.ConnectionPool(
                  "MySQLdb",
                  host=self.application.config["viper.mysql"]["host"],
                  port=int(self.application.config["viper.mysql"]["port"]),
  
                  user=self.application.config["viper.mysql"]["username"],
                  passwd=self.application.config["viper.mysql"]["password"],
  
                  db=self.application.config["viper.mysql"]["name"],
                  charset=self.application.config["viper.mysql"]["charset"],
  
                  cp_min=int(
                      self.application.config["viper.mysql"]["connectionsMinimum"]
                  ),
                  cp_max=int(
                      self.application.config["viper.mysql"]["connectionsMaximum"]
                  ),
                  cp_reconnect=True
              )
          except Exception as e:
              self.log.error(
                  "[Viper.MySQL] Cannot connect to server. Error: {error}",
                  error=str(e)
              )
  
          if "init" in self.application.config["viper.mysql"] \
                  and self.application.config["viper.mysql"]["init"]["runIfEmpty"]:
              self._checkIfDatabaseIsEmpty(
                  lambda isEmpty:
                      self._scheduleDatabaseInit(isEmpty)
                  ,
                  lambda error:
                      self.log.error("[Viper.MySQL] Cannot check if database is empty. Error {error}", error=error)
              )