class_docstr: This analyzer calculates the AnnualReturns by looking at the beginning
  and end of the year
  
  Params:
  
    - (None)
  
  Member Attributes:
  
    - ``rets``: list of calculated annual returns
  
    - ``ret``: dictionary (key: year) of annual returns
  
  **get_analysis**:
  
    - Returns a dictionary of annual returns (key: year)
code: def get_analysis(self):
      return self.ret
  
file_path: backtrader/backtrader/analyzers/annualreturn.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  from collections import OrderedDict
  from backtrader.utils.py3 import range
  from backtrader import Analyzer
label_desc: Use image node_id 2 for calling the AnnualReturn obj's underlying member method code with example usage: obj.get_analysis() and returns: self