code: def _parse(self):
          '''parse is the base function for parsing the Dockerfile, and extracting
             elements into the correct data structures. Everything is parsed into
             lists or dictionaries that can be assembled again on demand. 
  
             Environment: Since Docker also exports environment as we go, 
                          we add environment to the environment section and 
                          install
  
             Labels: include anything that is a LABEL, ARG, or (deprecated)
                     maintainer.
  
             Add/Copy: are treated the same
  
          '''
          parser = None
          previous = None
  
          for line in self.lines:
  
              parser = self._get_mapping(line, parser, previous)
  
              # Parse it, if appropriate
              if parser:
                  parser(line)
  
              previous = linf _parse(self):
          '''parse is the base function for parsing the Dockerfile, and extracting
             elements into the correct data structures. Everything is parsed into
             lists or dictionaries that can be assembled again on demand. 
  
             Environment: Since Docker also exports environment as we go, 
                          we add environment to the environment section and 
                          install
  
             Labels: include anything that is a LABEL, ARG, or (deprecated)
                     maintainer.
  
             Add/Copy: are treated the same
  
          '''
          parser = None
          previous = None
  
          for line in self.lines:
  
              parser = self._get_mapping(line, parser, previous)
  
              # Parse it, if appropriate
              if parser:
                  parser(line)
  
              previous = line
docs: parse is the base function for parsing the Dockerfile, and extracting
             elements into the correct data structures. Everything is parsed into
             lists or dictionaries that can be assembled again on demand. 
  
             Environment: Since Docker also exports environment as we go, 
                          we add environment to the environment section and 
                          install
  
             Labels: include anything that is a LABEL, ARG, or (deprecated)
                     maintainer.
  
             Add/Copy: are treated the same