text: from __future__ import unicode_literals
  
  import time
  import re
  
  from netmiko.base_connection import BaseConnection
  
  
  class F5LtmSSH(BaseConnection):
  
      def session_preparation(self):
          """Prepare the session after the connection has been established."""
          delay_factor = self.select_delay_factor(delay_factor=0)
          self.set_base_prompt()
          self.disable_paging(command="\nset length 0\n")
          time.sleep(1 * delay_factor)
          self.tmsh_mode()
          self.set_base_prompt()
  
      def tmsh_mode(self, delay_factor=1):
          """tmsh command is equivalent to config command on F5."""
          delay_factor = self.select_delay_factor(delay_factor)
          self.clear_buffer()
          self.write_channel("\ntmsh\n")
          time.sleep(1 * delay_factor)
          self.clear_buffer()
          return None
  
      @staticmethod
      def normalize_linefeeds(a_string):
          """Convert '\r\n' or '\r\r\n' to '\n, and remove '\r's in the text."""
          newline = re.compile(r'(\r\n|\r\n\r\n|\r\r\n|\n\r|\r)')
          return newline.sub('\n', a_string)
  