docstr: Workflow used to test variable string error.
  
  Parameters
  ----------
  positional_variable_str : variable string
      fake input string param
  positional_variable_int : variable int
      fake positional param (default 2)
  out_dir : string
      fake output directory (default '')
docstr_tok: ["Workflow","used","to","test","variable","string","error",".","Parameters","--","--","--","--","--","positional_variable_str",":","variable","string","fake","input","string","param","positional_variable_int",":","variable","int","fake","positional","param","(","default","2",")","out_dir",":","string","fake","output","directory","(","default","``",")"]
code: def run(
      self, positional_variable_str, positional_variable_int, out_dir=""
  ):
      """Workflow used to test variable string error.
  
      Parameters
      ----------
      positional_variable_str : variable string
          fake input string param
      positional_variable_int : variable int
          fake positional param (default 2)
      out_dir : string
          fake output directory (default '')
      """
      result = []
      io_it = self.get_io_iterator()
  
      for variable1, variable2 in io_it:
          result.append((variable1, variable2))
  
      return result
  
imports: from dipy.workflows.workflow import Workflow
  from dipy.workflows.combined_workflow import CombinedWorkflow
label_desc: Use image node_id 2 for calling the DummyVariableTypeErrorWorkflow obj's underlying member method code with example usage: obj.run(positional_variable_str, positional_variable_int, out_dir) and returns: result