parameters: (self, struct_name, range_start, field_options)
docstring: Implements a special pb_extension_t* field in an extensible message
          structure. The range_start signifies the index at which the extensions
          start. Not necessarily all tags above this are extensions, it is merely
          a speed optimization.
docstring_summary: Implements a special pb_extension_t* field in an extensible message
          structure. The range_start signifies the index at which the extensions
          start. Not necessarily all tags above this are extensions, it is merely
          a speed optimization.
docstring_tokens: Implements a special pb_extension_t * field in an extensible message structure . The range_start signifies the index at which the extensions start . Not necessarily all tags above this are extensions it is merely a speed optimization .
function: def __init__(self, struct_name, range_start, field_options):
          '''Implements a special pb_extension_t* field in an extensible message
          structure. The range_start signifies the index at which the extensions
          start. Not necessarily all tags above this are extensions, it is merely
          a speed optimization.
          '''
          self.tag = range_start
          self.struct_name = struct_name
          self.name = 'extensions'
          self.pbtype = 'EXTENSION'
          self.rules = 'OPTIONAL'
          self.allocation = 'CALLBACK'
          self.ctype = 'pb_extension_t'
          self.array_decl = ''
          self.default = None
          self.max_size = 0
          self.max_count = 0
          self.inline = None
function_tokens: def __init__ ( self , struct_name , range_start , field_options ) : self . tag = range_start self . struct_name = struct_name self . name = 'extensions' self . pbtype = 'EXTENSION' self . rules = 'OPTIONAL' self . allocation = 'CALLBACK' self . ctype = 'pb_extension_t' self . array_decl = '' self . default = None self . max_size = 0 self . max_count = 0 self . inline = None