parameters: (self)
docstring: Returns a map (filename, lineno) -> (filename, lineno, function_name).
docstring_summary: Returns a map (filename, lineno) -> (filename, lineno, function_name).
docstring_tokens: Returns a map ( filename lineno ) - > ( filename lineno function_name ) .
function: def get_effective_source_map(self):
      """Returns a map (filename, lineno) -> (filename, lineno, function_name)."""
      raise NotImplementedError('subclasses need to override this')
function_tokens: def get_effective_source_map ( self ) : raise NotImplementedError ( 'subclasses need to override this' )