class_docstr: This analyzer reports the transactions occurred with each an every data in
  the system
  
  It looks at the order execution bits to create a ``Position`` starting from
  0 during each ``next`` cycle.
  
  The result is used during next to record the transactions
  
  Params:
  
    - headers (default: ``True``)
  
      Add an initial key to the dictionary holding the results with the names
      of the datas
  
      This analyzer was modeled to facilitate the integration with
      ``pyfolio`` and the header names are taken from the samples used for
      it::
  
        'date', 'amount', 'price', 'sid', 'symbol', 'value'
  
  Methods:
  
    - get_analysis
  
      Returns a dictionary with returns as values and the datetime points for
      each return as keys
code: def start(self):
      super(Transactions, self).start()
      if self.p.headers:
          self.rets[self.p._pfheaders[0]] = [
              list(self.p._pfheaders[1:])
          ]
  
      self._positions = collections.defaultdict(Position)
      self._idnames = list(enumerate(self.strategy.getdatanames()))
  
file_path: backtrader/backtrader/analyzers/transactions.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import collections
  import backtrader
  from backtrader import Order, Position
label_desc: Use image node_id 1 for calling the Transactions obj's underlying member method code with example usage: obj.start() without return types