input: def VersionControl(lines):
      """
      Implement a basic version control system in Python that keeps track of changes in the code.
      The system should allow for committing changes and restoring to a previous commit.
  
      >>> vc = VersionControl([1, 2, 3])
      >>> vc.commit()
      >>> vc.commit()
      >>> vc.restore()
      >>> vc.lines
      [1, 2, 3]
      """
      def __init__(self, lines):
          self.lines = lines
          self.mark = 0
   
      def commit(self):
          self.mark += 1
          log_file = open("log_file.txt", "a+")
          log_file.write(str(self.mark) + ": " + str(self.lines))
          log_file.close()
   
      def restore(self):
          log_file = open("log_file.txt", "r")
          lines = log_file.readlines()
          to_mark = self.mark-1
   
          self.lines = lines[to_mark]
          log_file.close()
output:     
          self.lines = eval(self.lines.split(": ")[1])
  