class_docstr: An algorithm that ensures that 'phantom' positions do not appear in
  portfolio.positions in the case that a position has been entered
  and fully exited.
class_docstr_tok: ["An","algorithm","that","ensures","that","'phantom","'","positions","do","not","appear","in","portfolio.positions","in","the","case","that","a","position","has","been","entered","and","fully","exited","."]
code: def initialize(self, sids, *args, **kwargs):
      self.ordered = False
      self.exited = False
      self.sids = sids
  
imports: import numpy
  from nose.tools import assert_raises
  from six import itervalues
  from zipline.algorithm import TradingAlgorithm
  from zipline.api import FixedSlippage, order, set_slippage, record, sid
  from zipline.errors import UnsupportedOrderParameters
  from zipline.finance.execution import LimitOrder, MarketOrder, StopLimitOrder, StopOrder
label_desc: Use image node_id 1 for calling the EmptyPositionsAlgorithm obj's underlying member method code with example usage: obj.initialize(sids) without return types