old_contents: '''
  Created on 17.02.2015
  
  @author: marscher
  '''
  
  
  def build_chain(transformers, chunksize=None):
      """
      utility method to build a working pipeline out of given data source and
      transformers
      """
  
      for i in xrange(1, len(transformers)):
          transformers[i].data_producer = transformers[i - 1]
  
      if chunksize is not None:
          for t in transformers:
              t.chunksize = chunksize
  
      return transformers
  
  
  def run_chain(chain):
      for c in chain:
          c.parametrize()
  
new_contents: '''
  Created on 17.02.2015
  
  @author: marscher
  '''
  
  
  def build_chain(transformers, chunksize=None):
      """
      utility method to build a working pipeline out of given data source and
      transformers
      """
  
      for i in xrange(1, len(transformers)):
          transformers[i].data_producer = transformers[i - 1]
  
      if chunksize is not None:
          for t in transformers:
              t.chunksize = chunksize
  
      return transformers
  
  
  def run_chain(chain):
      for c in chain:
          if hasattr(c, 'parametrize'):
              c.parametrize()
  
subject: check if parametrize method exists before calling it.