input: Write a function to implement a basic version control system in Python that keeps track of changes in the code. The function should define a class `VersionControl` with methods to initialize the version control system with initial lines of code, commit the current state, and restore to a previous state.
  
  
  class VersionControl:
      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()
  
  vc = VersionControl(["initial line of code"])
  vc.commit()
  vc.commit()
  vc.restore()
  assert vc.lines == "1: ['initial line of code']"
  
  vc = VersionControl(["new line", "another line"])
  vc.commit()
  vc.commit()
  vc.restore()
  assert vc.lines == "2: ['new line', 'another line']"
  
  vc = VersionControl([])
  vc.commit()
  vc.commit()
  vc.restore()
  assert vc.lines == "2: []"
  
output: 
  class VersionControl:
      def __init__(self, lines):
          self.lines = lines
          self.history = []
          self.mark = 0
  
      def commit(self):
          self.mark += 1
          self.history.append(self.lines[:])
  
      def restore(self):
          if self.mark > 0:
              self.mark -= 1
              self.lines = self.history[self.mark][:]
  