class_docstr: This observer keeps track of the current cash amount and portfolio value in
  the broker (including the cash)
  
  Params: None
class_docstr_tok: ["This","observer","keeps","track","of","the","current","cash","amount","and","portfolio","value","in","the","broker","(","including","the","cash",")","Params",":","None"]
code: def start(self):
      if self.p.fund is None:
          self._fundmode = self._owner.broker.fundmode
      else:
          self._fundmode = self.p.fund
  
      if self._fundmode:
          self.plotlines.cash._plotskip = True
          self.plotlines.value._name = "FundValue"
  
file_path: backtrader/backtrader/observers/broker.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  from ..None import Observer
label_desc: Use image node_id 1 for calling the Broker obj's underlying member method code with example usage: obj.start() without return types