nodes: 0, module; 1, function_definition; 2, function_name:get_genetic_map_HapMapII_GRCh37; 3, parameters; 4, block; 5, identifier:self; 6, expression_statement; 7, if_statement; 8, return_statement; 9, comment:""" Get International HapMap Consortium HapMap Phase II genetic map for Build 37.
  
          Returns
          -------
          dict
              dict of pandas.DataFrame HapMapII genetic maps if loading was successful, else None
          """; 10, comparison_operator:self._genetic_map_HapMapII_GRCh37 is None; 11, block; 12, attribute; 13, attribute; 14, None; 15, expression_statement; 16, identifier:self; 17, identifier:_genetic_map_HapMapII_GRCh37; 18, identifier:self; 19, identifier:_genetic_map_HapMapII_GRCh37; 20, assignment; 21, attribute; 22, call; 23, identifier:self; 24, identifier:_genetic_map_HapMapII_GRCh37; 25, attribute; 26, argument_list; 27, identifier:self; 28, identifier:_load_genetic_map; 29, call; 30, attribute; 31, argument_list; 32, identifier:self; 33, identifier:_get_path_genetic_map_HapMapII_GRCh37
code: def get_genetic_map_HapMapII_GRCh37(self):
          """ Get International HapMap Consortium HapMap Phase II genetic map for Build 37.
  
          Returns
          -------
          dict
              dict of pandas.DataFrame HapMapII genetic maps if loading was successful, else None
          """
          if self._genetic_map_HapMapII_GRCh37 is None:
              self._genetic_map_HapMapII_GRCh37 = self._load_genetic_map(
                  self._get_path_genetic_map_HapMapII_GRCh37()
              )
  
          return self._genetic_map_HapMapII_GRCh37